A flamethrowing reliever has become a surprise addition to MLB free agency.

The A’s non-tendered Blake Treinen on Monday, making the 2018 All-Star a new hot commodity for teams seeking bullpen help.

The 31-year-old Treinen had been rumored as a trade candidate in the days leading up to Monday’s non-tender deadline, with the Yankees reportedly interested in acquiring him. But a deal never materialized and instead the A’s made Treinen a free agent, declining to pay him the projected $7.8 million he was set to earn in arbitration.

Despite being a newcomer to the market, Treinen is already receiving “immediate and heavy” interest, according to ESPN. He is only one year removed from being one of the most dominant closers in the league, when he saved 38 games and posted a 0.78 ERA and 0.834 WHIP while striking out 100 in 80 1/3 innings.

Last season, Treinen, who averages around 97 miles-per-hour on his fastball, came back to earth with a 4.91 ERA, 1.62 WHIP and 59 strikeouts in 58 2/3 innings. He went on the injured list in June with a shoulder strain and lost his job as closer by the time he came back. He was later shut down in September with a back injury.

With Will Smith (Braves) and Drew Pomeranz (Padres) already signing, the other top relievers left on the market include Will Harris, Daniel Hudson and Dellin Betances.