Cubs Place Jon Lester On Disabled List, But It's Expected To Be A Short Stint

(CBS) The Cubs breathed a sigh of relief Friday regarding left-hander Jon Lester's injury.

Lester has be placed on a 10-day disabled list after leaving with left lat tightness Thursday, but it's expected to be a shorter stint and isn't a season-ending injury. The Cubs considered the news encouraging and also said Lester has general shoulder fatigue in addition to the lat tightness. His shoulder is structurally sound, the team added.

The Cubs also placed right-handed reliever Justin Grimm on the 10-day DL with a right index finger infection. Grimm allowed the go-ahead homer in the seventh inning of Chicago's 13-10 loss to Cincinnati on Thursday. He has a 5.40 ERA in 39 appearances.

The Cubs called up left-handed reliever Rob Zastryzny and right-handed reliever Felix Pena in place of Lester and Grimm. Zastryzny has one appearance for the Cubs this season, allowing three earned runs in four innings. Pena has a 4.50 ERA in 16 innings across 10 appearances this year.

Lester left in the second inning of a loss to the Reds on Thursday afternoon after getting rocked to the tune of nine runs allowed, seven earned, in 1 2/3 innings. He was taken for examinations at Northwestern Memorial Hospital during the game.

Lester is 8-7 with a 4.37 ERA and 1.27 WHIP on the season. Left-hander Mike Montgomery is expected to take Lester's spot in the rotation.

Still, the Cubs will need their ace Lester down the stretch, as they're locked in a tight NL Central race. Entering play Friday, Chicago leads Milwaukee by one game and St. Louis by 1.5 games.

The Cubs host the Blue Jays on Friday afternoon at Wrigley Field.