Last week's 5 biggest fantasy surprises: Is Alejandro Kirk already a star at catcher?

Catcher is the most difficult position to draft in fantasy baseball. You either overspend to secure an elite option or shop in the bargain bin and hope for the best.

Choosing the bargain bin option is always risky. Unless you find that particular season's breakout star, you're likely playing the waiver wire and hoping to catch a player on a hot streak.

If you're lucky, you already picked up Tyler Stephenson on the waiver wire and are reaping the benefits.

If you missed out, you might have gotten an even better consolation prize in Toronto Blue Jays catcher, Alejandro Kirk.

Ranks are based on standard Yahoo fantasy leagues

Alejandro Kirk, Toronto Blue Jays C

Fantasy rank over the last seven days: 1

Season-long fantasy rank: 244

If you aren't familiar with Kirk, it's easy to look at his strong start as a fluke. Kirk hit .242/.328/.436 as a rookie. Those aren't bad numbers for a catcher, but they don't stand out either.

Based on his 2022 numbers, that 2021 slash line was misleading. Kirk was limited by an awful .234 BABIP in 2021.

Things have rebounded in a big way this season. Kirk is hitting .306/.389/.465 in 47 games, and a large portion of his breakout looks legit. Kirk has shown strong mastery of the strike zone this season, walking at a 12.6 percent clip and striking out just 9 percent of the time. His contact rate is a career-high 88.2 percent and his swinging strike rate is a low 4.9 percent, suggesting his lack of strikeouts and elevated batting average are here to stay. Kirk also has a max exit velocity in the 75th percentile, a sign he could provide above-average power.

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Kirk made Baseball America's and Baseball Prospectus' top prospect list heading into the 2021 MLB season. Though he ranked near the bottom on both lists, he was clearly seen as a talented player. That makes it easier to buy Kirk's breakout. All signs indicate a talented player has taken a big step forward.

A catcher who can hit for a high average and provide decent pop is a rare thing these days. If you bought in on Kirk, congratulations: You won the waiver wire lottery.

Jordan Montgomery, New York Yankees SP

Fantasy rank over the last seven days: 101

Season-long fantasy rank: 213

New York Yankees pitcher Jordan Montgomery has just one win this season, which is a shame given how well he's pitched. Montgomery has a career-best 3.02 ERA over 11 starts, the overlooked player in a dominant Yankees' rotation.

Montgomery isn't an overwhelming pitcher by any means, as evidenced by his 19.4 percent strikeout rate (that number is down from 24.5 percent last season). That would normally be a cause for concern, but it looks like Montgomery made an adjustment to his repertoire that could explain his drop in strikeout rate.

Montgomery has decided to become a dominant sinkerballer. After throwing the pitch nearly 22 percent of the time last season, Montgomery is using his sinker a third of the time in 2022 — and getting fantastic results.

Batters are hitting .236 against the pitch, putting it on the ground when they do make contact; Montgomery is running an elevated 47.1 percent ground ball rate in 2022. It's not all due to his sinker, but the pitch has been effective. It helps that Montgomery is getting more vertical and horizontal movement on the pitch, according to Baseball Savant.

Montgomery isn't suddenly going to become a top-10 fantasy pitcher, however. He lacks the strikeout upside to get there and the Yankees typically don't let him throw too many pitches. But his new approach makes him a threat to go deep into games more often and pick up quality starts. He's done enough to warrant a roster spot on most fantasy teams and is, at the very least, a strong streaming option most weeks.

Justin Turner, Los Angeles Dodgers 3B

Fantasy rank over the last seven days: 553

Season-long fantasy rank: 279

Is Justin Turner still a viable fantasy asset? Through 50 games, it's tough to tell. Turner has a .223/.291/.375 slash line and just 4 home runs.

There are still some things to like about his game. His strikeout and walk rates remain solid and he's still barreling the ball at a consistent clip. Problem is, the ball isn't being hit as hard. Turner's average exit velocity is down from 90.9 mph to 88.7 mph. He's also reaching more, making less contact and seeing an increase in his swinging strike rate.

Perhaps the most worrying sign with Turner is his inability to hit fastballs. Turner used to feast on heaters, but he's hitting .220 against the pitch in 2022. It's possible an injury is limiting his effectiveness. Turner has been primarily playing designated hitter and manager Dave Roberts confirmed Turner's hamstring was bothering him.

If that doesn't explain Turner's struggles, then it's tough to ignore his age. Turner is 37 now and it is possible Father Time has finally come for him. Sure, the struggles against fastballs could be a mechanical issue. It also could be slowing bat speed. Fantasy managers can continue to wait it out if their team is doing well, but there's enough here to be concerned about going forward.

Andrés Giménez, Cleveland Guardians 2B, SS

Fantasy rank over the last seven days: 18

Season-long fantasy rank: 90

It seems silly to call 23-year-old Andrés Giménez a long-time prospect, but he first appeared on prospect lists in 2018. Giménez made Baseball America's top-100 prospect list three times, his most recent appearance coming before the 2021 MLB season.

Giménez struggled in 63 games with the Guardians, hitting .218/.282/.351. Though he had a prospect pedigree, his performance didn't inspire much confidence going into 2022.

After 42 games this year, Giménez deserves recognition. He's hitting .307/.329/.540, with 7 home runs and 4 stolen bases. Those numbers are mostly legitimate. Giménez is barreling the ball more and making harder contact. His exit velocity is up over 3 mph and ranks in the 63rd percentile in MLB. His max exit velocity of 109.3 percent doesn't hint at elite power, but he should hit enough home runs to provide value in that category. Even if the power falls off, Giménez's sprint speed sits in the 96th percentile, a sign he will continue to swipe bases.

There are two main reasons to be wary of Giménez, however. First off, his .361 BABIP is probably going to drop. Giménez is fast, suggesting he can carry a higher BABIP than usual, but it's tough to sustain a .361 BABIP all season. That's especially hard to do when you don't have a strong strikeout-to-walk ratio. Giménez is striking out at a 23.6 percent clip and walking in just 2.8 percent of his plate appearances. At the same time, he's cut down significantly on his chase rate, and his swinging strike rate is down.

All of this suggests regression is coming, but it might not be enough to sink Giménez's value. He may be playing over his head at the moment, but Giménez has made enough improvement to be a usable fantasy option moving forward.

Charlie Morton, Atlanta Braves SP

Fantasy rank over the last seven days: 607

Season-long fantasy rank: 957

Is this the beginning of the end for Atlanta Braves starter, Charlie Morton? Through 54 1/3 innings, it's been pretty bad for the 38-year-old. Morton carries an abysmal 5.63 ERA and 1.53 WHIP through 11 starts.

The underlying stats don't look pretty. Morton's strikeout rate is down, his walk rate is up and his fly-ball rate has jumped. When batters are making contact, they are putting the ball in the air, which could be the reason for Morton's elevated home run rate. His velocity is fine though, but that leads to even more questions about his struggles.

Based on his pitch maps, it looks as if Morton is leaving more pitches over the heart of the plate in 2022. His 4-seam fastball is going right down the center of the plate, his curveball isn't dipping as low and his changeup isn't getting in on right-handers. Morton's walk rate remains high, however, so this could be an issue of Morton falling behind hitters early and then getting crushed when he has to put a pitch over the plate.

Given that Morton's velocity is strong, there's a chance he just needs to straighten out his mechanics to return to form. It's impossible to predict when that switch will flip, however, putting fantasy managers in a tough spot. His age and the fact that he's coming off a fractured fibula aren't encouraging signs either.

Morton is probably worth benching until he turns in a good start. If that doesn't happen soon, fantasy managers may need to think about cutting bait.