TORONTO -- A.J. Burnett played catch on Sunday, and the pitcher still experienced pain in his right shoulder. That being the case, Blue Jays manager John Gibbons said the club would likely need to place Burnett on the 15-day disabled list.

"He was still a little tender," Gibbons said after Toronto's 4-2 loss to Washington. "So, he won't make that start Saturday. We're probably going to have to throw him on the DL. We'll know more Tuesday."

During the fifth inning of Burnett's last outing, a road start against the Giants last Tuesday, the right-hander exited the game after feeling pain in his throwing shoulder. Burnett initially believed the discomfort stemmed from fatigue, considering he had thrown 372 pitches over his previous three starts.

Burnett and Gibbons each said the injury didn't appear to be serious, and the Blue Jays hoped he'd be able to avoid his ninth career trip to the DL. Now, that doesn't appear to be the case. If Burnett is placed on the DL, it will be retroactive to Wednesday, meaning he would be able to be activated on schedule on June 28.

"All indications are that it's not [too serious]," said Gibbons, who added that he hoped Burnett would be able to come off the DL on schedule. "But, any time you're a little stiff or a little sore, you've got to get rid of that before you go back out there."

With Burnett temporarily out of the picture, the Blue Jays will need to add a starter for Saturday's home game against the Rockies. Gibbons said Toronto would most likely call someone up from the Minor Leagues, but he declined to elaborate on which pitchers might be candidates.

Burnett, 30, is 5-6 with a 4.00 ERA and 100 strikeouts in 14 starts this season for the Blue Jays. Last year, which was the pitcher's first with Toronto after signing a five-year contract worth $55 million, Burnett spent more than two months on the DL with an elbow injury.

If Burnett is placed on the DL, he will become the 12th Blue Jays player to land on the list this season. Toronto currently has eight players, including six pitchers, on the DL with various injuries.

Burnett declined comment, but said he would discuss the injury on Tuesday, following Monday's off-day.