The Cubs have already added lefties Mike Montgomery and Aroldis Chapman to their bullpen this trading season, and now they've made it a third. It's now Joe Smith, with the Angels getting a minor-league pitcher in return, the Cubs have announced.

Smith is a low-velocity sidewinder, so he'll make for an interesting change of pace and style from the Cubs' arsenal of flame-throwers at the back-end like Chapman, Hector Rondon and Pedro Strop. Smith so far this season has a 3.82 ERA, 1.30 WHIP and 25 strikeouts in 37 2/3 innings. From 2011-14, he had a 2.25 ERA, but he's regressed a bit the past two seasons.

Joe Smith is bound for Chicago. USATSI

In return, the Cubs send 20-year-old right-hander Jesus Castillo to the Angels. Castillo is 2-3 with a 3.27 ERA, 1.18 WHIP and 38 strikeouts in 33 innings in Low-A this season. So there's some upside there, but it won't be untapped for a few years. Given the current situations of the Cubs and Angels, he makes perfect sense to include here.

Don't expect Smith to get much work in the late innings. Chapman is the closer with Rondon being a stellar setup man. Strop is still probably the seventh inning guy with Smith joining Travis Wood, Joe Nathan, Carl Edwards Jr., Montgomery et al as the other options in what has become a very deep Chicago bullpen.