If everything goes according to plan, Marcum could rejoin Toronto's rotation during the first week of August.
"Assuming no setbacks," Blue Jays assistant general manager Alex Anthopoulos said at Tropicana Field on Tuesday.
On Monday, Marcum logged three innings in a start for Class A Dunedin, marking his first game appearance since going under the knife at the end of last season. The 27-year-old right-hander threw 37 pitches, struck out one batter and gave up two hits to the 11 hitters he faced.
"He looked very sharp," said Anthopoulos, who met with Marcum on Tuesday in Florida. "All the reports are that he looked good and felt good. His next outing, he's scheduled to go four innings. He's excited. Tentatively, we have him scheduled to be back up in Toronto the first week of August."
That is a bit of good news for a Blue Jays pitching staff that has been plagued with injuries this season. Including Marcum and right-hander Dustin McGowan (right shoulder), who both opened the season on the disabled list, Toronto has had eight different starters shelved with an injury at some point this season.
The Blue Jays have cycled through 12 starting pitchers, including six rookies, in just 85 games, and they've had five rookies make their Major League debuts as a starter -- the most such cases in one season in club history. The latest was lefty Marc Rzepczynski, who was promoted from Triple-A Las Vegas to start against the Rays on Tuesday.
In 64 career starts for the Blue Jays, Marcum has gone 23-15 with a 3.85 ERA. He was moved into the rotation on a full-time basis during the 2007 season and was Toronto's No. 3 starter last season behind Roy Halladay and former Jays pitcher A.J. Burnett. Prior to injuring his arm last September, Marcum was 9-7 with a 3.39 ERA in 25 starts.
Jordan Bastian is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.