ST. PETERSBURG, Fla. - Oft-injured Toronto Blue Jays shortstop Jose Reyes is back on the disabled list after reinjuring his left hamstring in the first inning of his team's 9-2 Opening Day loss Monday to Tampa Bay.

Blue Jays manager John Gibbons said after the game that it was "a concern" that the injury occurred in the same place as a hamstring strain Reyes suffered in the final week of spring training.

"I tried to run a little bit faster between home plate and first base, and I kind of feel my hammy there," Reyes said Monday night. "So I have to slow down and get out of the game because I don't want to get any worse."

Reyes on Tuesday said the 15 days off "should be enough" to let his hamstring heal but added, "with hamstrings you never know."

An MRI taken Tuesday showed Reyes has mild inflammation.

"It is a relief," Reyes said. "That's good news. Just some inflammation there, no damage at all. Just some rest and I should be fine."

Reyes missed the Blue Jays' final five exhibition games in Florida because of the hamstring, then played five innings in each of their two preseason games in Montreal on Friday and Saturday. But he said after Monday's game that he "felt it" even in those two games, but "thought I could play through it."

In his first at-bat of the season, however, he hit a sinking line drive to center field, on which Rays center fielder Desmond Jennings robbed him of a hit with a diving catch. Reyes said that when he started to speed up halfway down the line, he felt his hamstring tighten. When he returned to the dugout, he told Gibbons immediately that he'd reinjured himself, and was replaced by Ryan Goins at short in the bottom of the first.

"When I tried for a little speed, something not right," Reyes said Monday.

Last season, in his first year with Toronto, Reyes spent 74 days on the disabled list with a severe ankle sprain, but during his Mets career he had four separate stints on the disabled list because of hamstring issues.

He had spoken repeatedly in spring training about wanting to play in all 162 games this season. So "this is very disappointing for me," he said Monday night.

The Blue Jays selected the contract of infielder Jonathan Diaz from Buffalo of the International League. Drafted by the Blue Jays in the 12th round of the 2006, he played in five games last season for the Red Sox -- making his major league debut against the Jays. He spent all but last season in the Blue Jays' organization.

Information from the Associated Press was used in this report.