Rays, Mariners swap prospects in five-player deal

In an unusual all-prospect trade, the Seattle Mariners last Friday traded prospects Dylan Thompson, Dalton Kelly, and Andrew Kittredge to the Tampa Bay Rays in exchange for prospects Richie Shaffer and Taylor Motter. Here's a brief look at each player.

Dalton Kelly, 1B: Kelly was a 38th round pick in 2015 by the Mariners from the University of California Santa Barbara. Playing for Low-A Clinton in the Midwest League in 2016, he hit .293/.384/.416 with 30 doubles, seven homers, 63 walks, and 21 stolen bases.

Age 22, Kelly is a left-handed hitter with less home run power than the typical first baseman but with a notable level of athleticism and above-average speed. He's a very good gloveman at first base and runs well enough to play the corner outfield spots if needed. He rates as a Grade C prospect for now until we see how his hitting holds up at higher levels.

Andrew Kittredge, RHP: Signed as an undrafted free agent from the University of Washington back in 2011, Kittredge has been bouncing up and down the Mariners system for years. In 2016 he posted a 3.50 ERA in 72 innings between Double-A and Triple-A with an 84/19 K/BB ratio.

Age 26, Kittredge can rack up strikeouts with a 90-96 MPH fastball, a hard slider, and a softer curve. His track record is erratic but he has a live arm and made progress harnessing his stuff this past year, giving him a chance to help in the Rays bullpen.

Taylor Motter, UT: A 17th round pick in 2011 from Coastal Carolina University, Motter split 2016 between Triple-A Durham (.229/.297/.389) and the Rays (.188/.290/.300). He did not hit well this year but his track record in past seasons was more impressive including a .292/.366/.471 line in Triple-A in 2015.

Age 27, Motter is an above-average athlete with good speed, some power, and a reasonable sense for the strike zone. Defensive versatility is his best asset: he can play every position except catcher due to his mobility, arm strength, instincts, and work ethic. He's a perfect 25th or 26th man on the roster.

Dylan Thompson, RHP: A fourth round pick in 2015 by the Mariners from high school in South Carolina, Thompson was limited to just 4.2 innings of work in 2016 due to a family health crisis (his father was stricken with cancer). He pitched 27 innings in rookie ball in 2015 and performed well (2.36 ERA, 25/8 K/BB).

Age 20, Thompson showed a 90-93 MPH fastball along with a plus curveball in high school but his stuff has taken a step backward in pro ball, most likely due to the lack of pitching time. At this point he is a speculative investment but should be watched closely for development once he gets back on the mound full-time.

Richie Shaffer, 1B-3B: The most prominent prospect in the trade, Shaffer was drafted by the Rays in the first round in 2012 out of Clemson. He had a strong 2015 season in Triple-A (.267/.357/.539 with 26 homers) but slumped in his second go-around the International League (.227/.329/.367). He got cups of coffee with Tampa in 2015 and 2016, hitting a combined .213/.310/.410 with 15 walks and 50 strikeouts in 122 at-bats.

Age 25, Shaffer has a strong right-handed power bat but has problems making consistent contact. He was shorter to the ball in '15 and produced well but his swing mechanics got out of whack in '16, perhaps out of frustration at not getting more of an opportunity in the majors despite his successful '15 season. His best position is first base but he can also play third base and the corner outfield spots if you don't mind his lack of range.