Keynan Middleton

Tommy John surgery has a fairly high success rate, but it's not 100%, and in the case of Middleton, the jury is still out as to whether he will make a complete recovery. Middleton did make it back to the majors last August, roughly 15 months after he went under the knife. However, his velocity was way down. His fastball clocked in at 94.1 mph on average, down two ticks, while his slider and changeup were down 3-4 mph. It was a small sample, but Middleton was far less effective. He struck batters out at an 18.2% clip, down more than seven percentage points from his debut in 2017, and his swinging-strike and O-Swing rates were 7.7% and 21.8%, respectively (MLB averages are around 9.5% and 30%). It certainly doesn't mean he should be written off, but Middleton is an unknown right now. Hansel Robles put his stamp on the closer job and Middleton is not high on the list of speculative stashes.

After an up-and-down rookie year in 2017, Middleton quickly emerged as one of the Angels’ top relievers in his sophomore season, taking over as the team’s closer in early April. The young right-hander converted six of his seven save chances before suffering a torn UCL in May that ended his season and forced him to undergo Tommy John surgery. Middleton posted a shiny 2.04 ERA prior to suffering the injury, though indicators -- mainly a dip in his K/BB from 3.5 K/BB in 2017 to 1.8 K/BB in 2018 and an unusually high strand rate (88.5%) -- suggest there could have been some luck at play (3.78 FIP). He did lower his home-run rate significantly from 2017. Middleton is set to miss a good chunk, if not all, of the 2019 season while recovering.

Don't chase wins, especially not relief-pitcher wins. Middleton racked up six wins while working out of the Angels' bullpen last season and even earned three saves as manager Mike Scioscia took a closer-by-committee approach for a while as the back end sorted itself out. He also had decent ratios to boot, but a 1.7 HR/9 and 84.7 percent left-on-base rate point to regression ahead. Plus, with Jim Johnson coming aboard via an offseason trade, there will be more competition for high-leverage work; a repeat of his six-win season would have been considered highly unlikely anyway. Middleton misses bats at a high rate, as evidenced by his 25.6 strikeout percentage and 16.6 percent swinging-strike rate, but his 2.8 BB/9 will be difficult to sustain with a 57.3 percent first-pitch strike rate. There are better options if you're looking to fill a mixed-league pitching staff with skilled middle relievers over fourth and fifth starters.