ST. PETERSBURG — The Tampa Bay Rays sent right-handed reliever Diego Castillo to Seattle Thursday, giving the Mariners a quick replacement for the back end of their bullpen. The Rays received reliever JT Chargois and a minor league infielder.

Castillo will likely jump into the closer role that was vacated when the Mariners traded Kendall Graveman to the Houston Astros earlier in the week. But unlike Graveman, who will be a free agent after the season, the Mariners gain a significant amount of control for the future with the acquisition of Castillo.

Castillo, 27, has 14 saves in 37 appearances and a 2.72 ERA this season for the Rays. He had a 1.66 ERA in 21 appearances during the shortened 2020 season for Tampa Bay. Castillo also appeared in 10 postseason games last year for Tampa Bay and allowed two earned runs in 11 innings.

More important for Seattle, Castillo will be under club control through 2024. It’s not a flashy move in the short term that will help Seattle compete with Oakland and the New York Yankees in the AL wild-card race. But it’s one that should make Seattle better in the future.

Chargois, 30, has been a solid addition to Seattle’s bullpen this season, making 31 appearances with a 3.00 ERA after not pitching in 2020. He’s primarily been a bridge option, pitching mostly in the sixth and seventh innings. Chargois had gone eight straight appearances without giving up an earned run before getting tagged for three runs by the Astros on Wednesday.

Also going to Tampa Bay is 23-year-old minor league infielder Austin Shenton. Shenton was a fifth-round pick by Seattle in 2019. He appeared in 67 games between High-A Everett and Double-A Arkansas this season, hitting .300 with 29 doubles, 12 homers and 61 RBI.