Brandon Brennan

A Rule 5 pick last winter, Brennan made a couple trips to the injured list but pitched reasonably well for Seattle when healthy, holding opponents to a .198 average. He's mostly a fastball/changeup pitcher, with the four-seamer averaging 94.8 mph last season. Both the fastball and the offspeed had groundball rates north of 50%, and the changeup had a 27.5% swinging-strike rate. Brennan had fairly dramatic platoon splits; he did a great job against same-handed hitters (.240 wOBA), but lefties knocked him around pretty good, to the tune of a .242/.354/.439 line. Perhaps he will start throwing his slider more -- breaking away from right-handers -- to combat those issues. At 28, Brennan does not have the upside of Carl Edwards Jr. or Sam Tuivailala, but he figures to have a fairly prominent role in the Mariners' bullpen.

The right-hander began the season at Double-A for the first time, but he was sent down after four dreadful (23 earned runs over 14.2 innings). He was at least serviceable as a starter for High-A Winston-Salem, compiling a 4.54 ERA with two complete games to finish his time at that level. This prompted a return to Double-A, although more struggles in the rotation led the 25-year-old to be moved to the bullpen, which only managed to help him lower his ERA to a horrific 8.09. Brennan improved his strikeout rate from the years prior, but his major control issues still lingered throughout the season. The fact that his FIP at Double-A was over four runs lower than his ERA is promising, but his lack of command will make it difficult for him to move up from Double-A during the 2017 season.