WASHINGTON -- Blue Jays ace Roy Halladay is tentatively scheduled to throw off a mound on Tuesday. It would be Halladay's first time working downhill since testing his strained right groin during a brief bullpen session at Citizens Bank Park on Wednesday.

Halladay is eligible to return from the 15-day disabled list on June 28 and the Toronto ace appears to be on pace to come back on time. Halladay's return will force the Blue Jays to juggle their rotation -- something the team is already doing this week in light of recent developments on the mound.

On Saturday night, the Jays' bullpen was taxed and the club was forced to use starter Scott Richmond in relief for one-plus innings in a 5-3 loss to the Nationals in 12 innings. Due to that appearance, Richmond's next scheduled start has been pushed back to Wednesday, when he will face the Reds in the second game of a three-game home series.

Left-hander Brian Tallet will start the opener against Cincinnati on Tuesday, pitching on only three days' rest. Tallet started for Toronto on Friday, but only threw 76 pitches over five innings before being pulled in favor of a pinch-hitter in the sixth inning of a 2-1 loss to Washington that lasted 11 frames. Left-handed rookie Brett Cecil will start in the finale against the Reds on Thursday.

Rookie Brad Mills, who lasted just 3 2/3 innings in his Major League debut for the Blue Jays on Thursday in Philadelphia, will be moved into the bullpen for the time being. Toronto will not require a fifth starter until next Saturday, meaning Mills will have had eight days off between starts, if he gets the nod for that upcoming contest at home against the Phillies.

Mills -- promoted after right-hander Casey Janssen (right shoulder inflammation) landed on the 15-day DL on Wednesday -- would be the most likely candidate to be returned to Triple-A Las Vegas upon Halladay's return. If Halladay (10-1, 2.53 ERA) is activated on June 28, he would also be in line to start the opener of a three-game set against the Yankees at Yankee Stadium on July 3.