Right-handed starter Zack Littell, the No. 37-ranked free agent available this season by The Athletic, has agreed to a free-agent deal with the Washington Nationals, a league source confirmed.

Littell, 30, was one of three unsigned pitchers among the Top 50 available free agents before agreeing to join the Nationals, leaving fellow right-handers Lucas Giolito (30) and Michael Kopech (50). The deal is pending a physical.

The Cincinnati Reds added Littell, 30, to their rotation in a deal with the Tampa Bay Rays at the trade deadline. Littell stepped in and helped the team’s starting depth, moving Nick Martinez to the bullpen full-time for the club’s playoff run.

Littell went 2-0 with a 4.39 ERA in 10 starts with the Reds and was 10-8 with a 3.81 ERA in 32 starts overall.

After being put on waivers by the Boston Red Sox in 2023, he was claimed by Tampa Bay and moved from the bullpen to the rotation. The North Carolina native made 14 starts for the Rays in 2023, carding a 4.10 ERA, and then went 8-10 with a 3.63 ERA in 29 starts in 2024.

With a fastball that averages just 91.9 mph, Littell’s strength is throwing strikes — and getting batters to chase balls. His 32 walks and 4.2 percent walk rate were both best among all qualified starters in baseball in 2025. Batters chased 30.8 percent of his pitches outside of the zone, putting him in the 79th percentile among big-league pitchers.

The 6-foot-4, 250-pound Littell mixes his five pitches, throwing his slider 28 percent of the time in 2025, followed by a splitter that he used 27 percent of the time and his four-seamer 24 percent. He also throws a sinker (16 percent) and mixes in a sweeper (5 percent).

Littell does give up hard contact and home runs. His 36 home runs allowed in 2025 were the second-most in baseball. That home run rate wasn’t helped by his move to Great American Ball Park. Of Littell’s 36 home runs allowed, 10 came in his five starts at Great American Ball Park, including two as a member of the Rays.

While Littell was in the back of the Reds’ rotation, he did start the second game of the National League Wild Card series against the Dodgers, allowing three runs on six hits in 3 1/3 innings. He’s also made five relief appearances in the postseason in stints with the Minnesota Twins, San Francisco Giants and the Rays.