"It's certainly not good for our staff," said Blue Jays manager Cito Gaston.

Ryan, who has blown two of his four save opportunities this season, is suffering from a tight trapezius muscle. Romero, off to a great start in his rookie season, has a right oblique muscle strain.

Ryan told Gaston the muscle in his back and shoulder was bothering him after Wednesday's game, where Ryan blew a 7-4 lead in the ninth inning by allowing three ninth-inning runs. Toronto went on to win 8-7 in 11 innings.

Romero said he first felt the problem before his April 14 start against the Minnesota Twins when he was wearing his headset and sneezed. He had pitched with the injury but it was decided to be cautious with him and put him on the DL.

In three starts this year, Romero, 24, is 2-0 with a 1.71 earned-run average. His DL stint is retroactive to April 20.

Gaston said the Blue Jays will announce their replacements today when they open a series against the White Sox in Chicago.

Two possibilities for call-ups from triple-A Las Vegas are right-handed reliever Jeremy Accardo who is 0-0 with a 3.00 ERA and three saves and left-handed starter Brian Burres who is 0-2 with a 6.97 ERA.

Romero's injury came just when Gaston felt his starting rotation was taking shape with Jesse Litsch due to return soon from an elbow injury. Toronto is already dealing with injuries to starters Shawn Marcum (elbow surgery) and Dustin McGowan (shoulder surgery) that will likely keep them out for the season.

"It's a shame because this kid (Romero) really pitched well for us," Gaston said. "I was just thinking (the other day) we get Jesse back and this kid continues to pitch the way he's been pitching and (Roy Halladay) pitches the way we know he can pitch, you've got three guys there that are really going to help you."