The St. Louis Cardinals have joined the Detroit Tigers among the clubs interested in Baltimore right-hander Jeremy Guthrie, major-league sources told FOXSports.com.

The extent of conversations between the Cardinals and Orioles is unknown, but St. Louis would like to add an established starter so Kyle McClellan can move back to the bullpen, where he has had more success.

Guthrie is 4-13 with a 4.35 ERA in 22 games this season. In some respects, he could be similar to Kyle Lohse – a longtime American Leaguer who didn’t become a consistent winner until moving to the National League and working with Cardinals pitching coach Dave Duncan.

-- Jon Paul Morosi and Ken Rosenthal