The Cubs finalized their rotation this weekend, announcing Carlos Villanueva would start Sunday's series finale against the Phillies.
With Jake Arrieta sidelined due to a shoulder injury in spring training, the Cubs broke camp with Villanueva slotted in the fifth-starter role. But thanks to a pair of extra-inning games in Pittsburgh, the 30-year-old swingman has already made two appearances out of the bullpen and thrown 30 pitches on the season.
Villanueva took the loss in both games, serving up a leadoff homer to Neil Walker in the 10th inning on Opening Day and then allowing the walk-off run in Wednesday's 16-inning marathon. Arrieta was slated to make a rehab start for Double-A Tennessee Saturday and may be back in the mix soon.
It's only four games into the season, but the Cubs' rotation has looked very good in the early going, entering play Saturday fourth in Major League Baseball with a 1.78 rotation ERA and third with a .172 batting average against.
"They've all been fantastic," Cubs manager Rick Renteria said. "They've been great."
The problem for the Cubs has been offense, as they've given their rotation just eight runs of support in five games, the lowest output in the majors.
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But the pitching has kept the Cubs in each game so far, which Renteria partially attributed to Welington Castillo's work behind the plate. The Cubs have spent a lot of time the last couple years working with the young catcher on how to call a game and Renteria likes what he's seen so far.
"Weli's doing a great job with the staff," Renteria said. "They're constantly communicating. This is a situation where he's really improved.
"Everybody saw improvement with him last year, but I think the confidence and the comfort they're starting to have with each other is big for our club."