Wilson hasn't pitched in a game in more than 15 months, but at least one scout who attended sent back a positive report.
"He looked good," the scout said. "His fastball was 90-93 mph. [He's] not far away."
Wilson is still just 31 years old, but he has twice undergone Tommy John surgery. He was reportedly unimpressive in an audition for the Mets in January, and he decided to continue working out on his own until he felt he was closer to 100 percent.
It's not yet clear which teams have the most interest in signing Wilson, but the Pirates, Diamondbacks, A's, Giants, Phillies, Rangers, Rockies and Cardinals were among the teams represented at Thursday's workout.
The Pirates, who just lost closer Jason Grilli to injury, could be a natural fit. So could the Diamondbacks, who have basically been operating without a closer.
The trade market for relievers has been thin, with no dependable closer definitely available.
Wilson has 171 career saves, more than all but six pitchers currently in the big leagues.