The Colorado Rockies are near the top of the NL West despite a struggling rotation.
He may be past his prime, but the Rockies are hoping Roy Oswalt can give the pitching staff a lift when he makes his season debut in the opener of a four-game series with the Washington Nationals on Thursday night.
Colorado (37-36) signed the 35-year-old Oswalt to a minor league contract May 2, and the right-hander went 3-2 with a 2.16 ERA in five starts for Double-A Tulsa. The three-time All-Star is 163-96 over 12 years, and he was 4-3 with a 5.80 ERA in 17 games - nine starts - last season for Texas.
"He's always a competitive guy, a tough at-bat," manager Walt Weiss told the Rockies' official website. "He's a nice piece to have. He's ready to go. His velocity is real good and throwing all his pitches. He's done just about everything in this game, pitched in big games and been a staff ace."
It's highly unlikely he will be as effective as he was for Houston nearly a decade ago when he recorded back-to-back 20-win seasons. The Rockies, though, expect he can stabilize a shaky rotation.
Since May 30, Colorado's starting staff has baseball's third-worst ERA at 5.26. The rotation has only five wins in the last 25 games, but the Rockies are within 2 1/2 games of division-leading Arizona.
Oswalt will be facing a Washington team that snapped a three-game losing streak with a 6-2, 11-inning victory in Philadelphia on Wednesday. Jayson Werth's RBI single with two outs in the ninth tied it for the Nationals (35-36), and two innings later Ian Desmond hit a grand slam.
"I think that's one of the best games we've had as a team all year," starter Gio Gonzalez said. "We battled, made adjustments and came out on top."
Desmond is batting .167 (4 for 24) lifetime against Oswalt - his lowest average of the 17 pitchers he has faced at least 18 times.
Oswalt is 7-5 with a 3.17 ERA in 19 starts against the Washington franchise, last facing the Nationals in 2011.
Washington counters with Jordan Zimmermann (9-3, 2.44 ERA), who is trying to bounce back from a subpar showing.
Zimmermann was tagged for six runs and eight hits - including two homers - in five innings against Cleveland on Saturday, but the Nationals rallied for a 7-6 win. It was just the second time in 11 starts the right-hander permitted more than two runs.
Returning to the nation's capital could help Zimmermann become the first Washington pitcher to earn 10 wins by June 20 since Livan Hernandez in 2005. Zimmermann is 6-0 with a 1.06 ERA in seven home games.
His last outing against the Rockies came at Nationals Park last July, and he allowed one run and three hits in seven innings but did not factor in the decision of a 4-3 loss. He is 3-0 with a 1.80 ERA in five career starts in the series.
The Nationals won two of three in Colorado last week. Desmond went 7 for 10 with five RBIs and Ryan Zimmerman was 4 for 11 with a homer, three doubles and four RBIs.
Tyler Colvin had two home runs and five RBIs in the series for Colorado, while Carlos Gonzalez homered, tripled and drove in four runs.
Gonzalez hit his NL-leading 21st home run in Wednesday's 5-2 loss in Toronto - Colorado's sixth defeat in eight games.
Gonzalez, who leads the NL with 45 extra-base hits, is batting .440 with three homers in six games since facing Washington.