The Mariners have some fine starters, but Castillo has to be the ace. He's a tough left-hander off a great season with a pair of overpowering scoreless starts to date. The Ms have not shone to start the season but have been fine in Castillo's starts. Cubs starter Smiyly struggled at the tail-end of preseason, and very much so in his first start. He will bounce back at some point, but I don't think he'll compare well to Seattle's ace on Monday.

The Mariners' pen is expected to be one of the best this season. They have been better than average so far, and shine in comparison to Cub's pen (5.02 to date). The Cubs have the edge on offense at the moment, but it will be tough to generate runs against the Seattle pitching staff. I have faith in the M's bats this season. Take the Mariners to win on Monday.