Former Kansas City Royals closer Greg Holland will pitch in a showcase for the first time since undergoing Tommy John surgery in 2015, with as many as 15 teams expected to be in attendance.

Holland, who missed the entire 2016 season, will hold the showcase Monday at Grand Canyon University in Phoenix. The Boston Red Sox, New York Yankees, Philadelphia Phillies, Miami Marlins, and San Francisco Giants are among the teams with the most interest, according to Jon Heyman of Today's Knuckleball.

When healthy, Holland is one of the most dominant late-inning arms in baseball, with a combined 1.97 ERA, 242 strikeouts, and converting 125 saves from 2013-15, receiving American League Cy Young votes in back-to-back seasons.

Relievers are expected to highlight the free agent market this winter, with Aroldis Chapman, Kenley Jansen, Mark Melancon, Brad Ziegler, Sergio Romo, and Holland headlining the group.