'Pen carrying heavy load, showing some wear

'Pen carrying heavy load, showing some wear

'Pen carrying heavy load, showing some wear

TORONTO -- The Blue Jays' bullpen is starting to show some signs of wear and tear after easily being the club's biggest strength through the first 100 games of the season.

Toronto's relievers entered play on Thursday night having allowed 18 earned runs over their past 13 1/3 innings. One reason for the recent struggles is that right-hander Josh Johnson recorded just six outs during his start on Monday night, and the bullpen has been running on fumes ever since.

That has been an ongoing concern for most of the season, as Toronto's relievers rank first in the Major Leagues with 356 1/3 innings pitched. The workload did appear to have an impact on left-hander Juan Perez, who surrendered five runs in one inning on Wednesday night, his third outing in Toronto's past four games.

"You figure sooner or later, he was going to give up something," manager John Gibbons said of Perez, who hadn't surrendered an earned run in 22 innings before Wednesday. "You can't argue with what he's done, how good he has been."

Johnson was available to pitch an inning out of the bullpen during Wednesday's series finale against the Dodgers, but things should be back to normal after starter Esmil Rogers recorded seven strong innings in the loss.

For the bullpen to remain stable, there's no question that the starting rotation will have to pick up some of the slack. The Blue Jays' rotation has thrown the second fewest number of innings in the Major Leagues this season with 548 1/3. The only team to receive less from their starters is the Twins, with 534 1/3 innings.

"We should be fine tonight, but we needed [Mark] Buehrle to throw some innings," Gibbons said prior to Thursday's matchup against the Astros.

Gregor Chisholm is a reporter for MLB.com. Read his blog, North of the Border, and follow him on Twitter @gregorMLB. This story was not subject to the approval of Major League Baseball or its clubs.