Waiver Wired: Sizzling Stephen

The big news -- non-Tom Brady division -- this morning is that the Dodgers are calling up top prospect Corey Seager. Before you rush to the waiver wire to pick him up in mixed leagues, consider that the move was partially done out of necessity, as Enrique Hernandez is on the disabled list and Jose Peraza is expected to miss a few days with a hamstring injury. The Dodgers needed some insurance at shortstop and they viewed Seager as the best option. He's super exciting for the long-term, so this should be a fun sneak preview, but playing time could be hard to come by over the next month.

As for some September call-ups who could play a role, watch this week's Buy, Sell, or Hold video.

Have a specific question about your roster? Ask @djshort on Twitter.

MIXED LEAGUES

Javier Baez 2B/SS, Cubs (Yahoo: 28 percent owned)

As I said in this week's Rotoworld Mailbag, Baez might be the most intriguing September call-up in fantasy leagues. The 22-year-old got the call this week after batting .324/.385/.527 with 13 home runs and 61 RBI over 70 games this season with Triple-A Iowa. The Cubs believe that he has made progress with his approach at the plate, also limiting the use of his leg kick. Baez hit just .169 with 95 strikeouts in 52 games during his first stint in the big leagues last season, but there's big-time power potential here and opportunity at second base with the Cubs. He's a fun lottery ticket down the stretch.

Kevin Jepsen RP, Twins (Yahoo: 26 percent owned)

Glen Perkins was unavailable for Wednesday's game due to continued back stiffness, so Jepsen filled in for the save against the White Sox. He should get more opportunities in the days to come, as Perkins required a precautionary MRI and will miss the start of the Twins' upcoming road trip. Jepsen has been great since coming over to the Twins at the trade deadline, posting a 1.15 ERA in 17 appearances while notching five saves. He's a must-own in all formats until there's more clarity on Perkins' situation.

Carl Crawford OF, Dodgers (Yahoo: 17 percent owned)

Crawford was brought back as a part-time player after missing close to three months with a torn oblique muscle, but he's getting most of the playing time in left field now that Yasiel Puig is out with a hamstring injury. The 34-year-old has swung the bat well over the past month and has six stolen bases in that time. Sure, he's not the player he once was, but it's easy to forget that he batted .300/.339/.429 just last season. The Dodgers will sit him against lefties, but he's still capable of helping in most formats.

Marcus Stroman SP/RP, Blue Jays (Yahoo: 13 percent owned)

My colleague Ryan Boyer discussed Stroman in this column last month, but he's worth mentioning again as he inches closer to his return. Working his way back from a torn ACL suffered during spring training, the 24-year-old tossed 4 2/3 hitless innings Wednesday in his first minor league rehab start with Class A Lansing. He struck out seven batters and walked just one while throwing 68 pitches. If all goes well in his next start on Monday with Triple-A Buffalo, he should rejoin the Blue Jays from there. Most assumed that Stroman was done for the year, so it's amazing that he has even made it this far. It's unfair to expect him to be effective right out of the gate, a DL stash is warranted at this point if you have the roster flexibility.

Stephen Piscotty OF, Cardinals (Yahoo: 40 percent owned)

Piscotty has provided quite the lift to the Cardinals' offense since his call-up in July. Functioning as the regular left fielder with Matt Holliday sidelined, the 24-year-old is batting .340/.374/.542 with four home runs, 11 doubles, three triples, 24 RBI, and 20 runs scored over 39 games. He's currently riding a 10-game hitting streak and has batted second in each of the last five games. Is he going to keep up this pace? Of course not. He has a .414 BABIP right now. But he has proven himself enough to be owned in most leagues.

Martin Prado 2B/3B/OF, Marlins (Yahoo: 34 percent owned)

With every game so crucial at this point in the fantasy calendar, there's nothing worse than finding out one of your regulars is getting a day off and not having anyone to fill in. That's where someone like Prado comes in handy. He's not going to make a major impact from a category perspective, but he's swinging the bat better since coming off the disabled list in July, including four multi-hit games in his last seven. Most importantly of all, he's eligible all over the place.

Drew Pomeranz RP/SP, Athletics (Yahoo: 19 percent owned)

I've been rooting for Sean Doolittle to find his way back into the closer role for the A's, as he's had some really bad luck on the injury front this year, but Pomeranz remains the pitcher to own in this bullpen. While the southpaw blew his most recent save opportunity on Sunday against the Diamondbacks, he has been really good in a relief role, posting a 2.16 ERA and 39/13 K/BB ratio over 33 1/3 innings. He hasn't given up a home run since making his move to the bullpen. Doolittle was really good last time out and I'm not ruling him out by any means, but Pomeranz could very well finish the year with the job.

Jayson Werth OF, Nationals (Yahoo: 39 percent owned)

Similar to Ryan Zimmerman, Werth is rounding into form at just the right time for the Nationals, who are fighting to keep their season alive. The 36-year-old got off to a slow start after missing two months with a pair of fractures in his left wrist, but he's hitting .306/.394/.581 with three home runs, six doubles, one triple, eight RBI, and 13 runs scored over his last 15 games. That's much closer to the production we have come to expect from him. With Denard Span officially done for the season after hip surgery, Werth should be the Nationals' regular leadoff man the rest of the way.

Shopping at the five-and-dime:

(Players owned in under 10 percent of Yahoo leagues)

Michael Conforto OF, Mets (Yahoo: 7 percent owned)

There were many questions about Conforto's readiness when he was called up to the majors in July, but he's leaving little doubt these days. The 22-year-old has gone deep in two out of his last three games and now owns a .311/.396/.567 batting line with five home runs, eight doubles, and 17 RBI through his first 106 plate appearances in the majors. He also has 20 strikeouts against 13 walks, so the approach has also been encouraging. It's worth noting that the Mets have played him almost exclusively against right-handed pitching and that isn't likely to change down the stretch. Conforto isn't an everyday option for fantasy owners, but he's certainly a worthwhile addition in leagues where you can make daily lineup changes.

Justin Bour 1B, Marlins (Yahoo: 3 percent owned)

Bour is doing his best to make sure he's in the Marlins' plans for 2016. The 27-year-old has homered in three out of his last five games and now owns a respectable .252/.321/.449 batting line on the year to go along with 15 homers and 49 RBI. According to the excellent Baseball Savant, Bour is 20th in the majors in average tracked exit velocity, which puts him among some impressive company. He has done most of his damage against right-handers (.799 OPS) while mostly sitting against southpaws, but his power should have him on the radar in more leagues.

Suitable streamers:

Joe Kelly SP, Red Sox (Yahoo: 19 percent owned)

Kelly might not get the American League Cy Young Award as he predicted back in January, but he's been on quite a roll recently. The 27-year-old has won each of his last six starts and has a 1.69 ERA in his last five. Not bad for a guy who was demoted to Triple-A back in June. While Kelly has switched up his pitch mix, the underlying numbers don't suggest we're seeing a major breakout here. He's still not getting a ton of swings and misses. However, he gets the Phillies on Friday and the Red Sox should score some runs, so it's a strong matchup.

Steven Matz SP, Mets (Yahoo: 47 percent owned)

As stated in the video above, the Mets are skipping Noah Syndergaard's start this weekend against the Marlins in order to manage his workload, which means that Matz will get an opportunity to fill in. Out since July 5 with a partially torn left lat muscle, the 22-year-old posted a 1.40 ERA in four minor league rehab starts, including 11 1/3 scoreless innings in Double-A. He was really impressive in his first two major league starts prior to the injury, so he's worth a shot against a lineup who might not have Giancarlo Stanton back as originally planned. With the Mets trying to manage the workloads of a couple of their starters, it's likely Matz will get more starts down the stretch.

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AL ONLY

Erik Johnson SP, White Sox (Yahoo: 0 percent owned)

Johnson showed some potential in 2013 before taking a step back last year, but he's back on the radar again after posting a 2.37 ERA and 136/41 K/BB ratio in 132 2/3 innings this season with Triple-A Charlotte. The White Sox included him among their September call-ups and plan to plug him into their rotation Sunday against the Royals. He's well worth a try.

J.P. Arencibia C/1B, Rays (Yahoo: 0 percent owned)

We know what Arencibia is. He doesn't hit for average and doesn't get on base often. However, he has some pop in his bat and he's capable of doing some damage when he actually makes contact. We have seen that so far this week, with homers in back-to-back games and a six-RBI game on Tuesday. Curt Casali is sidelined with a left hamstring strain, so Arencibia should continue to share playing time with Rene Rivera behind the plate for now. At catcher, you can live with him.

NL ONLY

Hector Olivera 3B, Braves (Yahoo: 0 percent owned)

After all the hype, Olivera is finally up in the big leagues and should function as the Braves' regular third baseman moving forward. Regarded as one of the best hitters in Cuba for over a decade, the 30-year-old received a $62.5 million contract with the Dodgers prior to being flipped to Atlanta at the trade deadline. Olivera missed a bunch of time in the minors this year with a hamstring injury and the numbers weren't overly impressive, but the playing time should be there as the Braves look toward 2016. I'm taking a wait and see approach in most mixed leagues, but he's obviously intriguing.

Alejandro De Aza OF, Giants (Yahoo: 4 percent owned)

The Giants picked up De Aza from the Red Sox just before the August 31 waiver deadline and figure to give him looks all around the outfield over the next month. The 31-year-old is not going to play everyday with Marlon Byrd, Gregor Blanco, Nori Aoki, and Angel Pagan also in the mix, but he offers speed and pop and good numbers against right-handed pitching.