With Jon Lester on IL, Cubs add LHP Tim Collins, giving them 9-man bullpen

With ace Jon Lester going on the injured list Wednesday, the Cubs responded by calling up left-hander Tim Collins to join what will now be a nine-man bullpen.

Collins, 29, was acquired the last week of spring training and has pitched in three games for Class AAA Iowa since then, allowing one run in 2 2/3 innings, with three strikeouts and a walk.

The move all but assures that Tyler Chatwood will take Lester’s next turn in the rotation, Sunday against Tommy La Stella and the Angels.

The Cubs have enough off days on the schedule after that to avoid needing to fill that spot again until April 27 in Arizona.

Left-handed swingman Mike Montgomery (lat) is eligible to return from the injured list Monday. As the Cubs’ sixth starter last season, he made a career-high 19 starts for injured and underperforming starters.

A glaring weakness the first eight games of the season, the bullpen takes a 12-inning scoreless streak into Wednesday night’s game against the Pirates.