Gillen's move to center field was a big success in 2025, and he now projects as a plus defender with plus speed that he uses on the bases. A prep shortstop, Gillen had shoulder surgery as an amateur that sapped his arm strength, forcing the move to the outfield. He managed a 151 wRC+ as a 19-year-old at Single-A, despite hitting just five home runs in 73 games. Gillen slashed .267/.433/.387 with a 19.8 percent walk rate, a 23.1 percent strikeout rate and 36 steals on 39 attempts in 324 plate appearances while missing time with calf and hand injuries. There's still a chance he breaks out as a power hitter in 2026 or 2027, given his excellent swing decisions and contact skill. The lefty-hitting Gillen hit all five homers against opposite-handed pitching and logged a .693 OPS against southpaws, and the Rays are typically utilizing one or two outfield platoons, so Gillen may sit or bat in the bottom third against lefties. Read Past Outlooks