Leyba tested positive for the performance-enhancing substance Boldenone, an anabolic steroid.
Bumgarner has been competing in rodeo events under the alias Mason Saunders.
MadBum won over $26,000 at Wickenburg rodeo in December under the name Mason Saunders.
Madison Bumgarner throws second bullpen session of spring
He hit a career-high .254 last season with 19 homers and 82 RBIs in 158 games.
Jay has .285 average over 10 MLB seasons.
Two-time Gold Glove winner hit 23 homers in 2019.
Star columnist Greg Hansen offers his take on Southern Arizona sports, from college baseball and college golf to high school basketball and track:
Outfielder batted .275 with 12 homers in 99 games last season.
Relief pitcher had 3.71 ERA in 62 games in 2019.
Calhoun, who lives in Tempe, hit 33 homers for Angels in 2019.
Arizona introduced pitcher at Chase Field on Tuesday.
Right-hander had 3.55 ERA in 71 games with Milwaukee in 2019.
The latest from Star columnist Greg Hansen.
Arizona's 40-man roster now has a full 40 players.
The Star's Greg Hansen writes about Arizona's uneven exhibition win, why the Wildcats' women's golf team is poised for big things and the late…
Dave Martinez was tossed in the seventh inning of Tuesday's Game 6.
Arizona won a surprising 85 games to finish second in NL West.
Arizona ends season with five straight wins and 85-77 record.
Arizona wraps up season with games Saturday and Sunday against San Diego.