"I just know that it won't be Downs today," Gaston said on Sunday, following a 12-inning loss to the Rays on Saturday in which Downs couldn't hold a 9-7 lead in the ninth, surrendering two solo home runs.
"It's something I'm going to think about and see what happens with that," Gaston said.
Downs, who became Toronto's closer after B.J. Ryan struggled in the role before eventually being released, has posted a solid 3.06 ERA in 32 appearances this year, recording nine saves in 12 opportunities.
In six appearances since returning from a sprained toe early this month, however, Downs has given up six runs -- five earned -- in five innings. He was charged with the loss in his two appearances prior to the blown save on Saturday. On Friday, he gave up two runs in the 10th inning, and on Tuesday, he could not hold a one-run lead, giving up two runs in the ninth for a blown save and a loss.
"I guess he'd be the first one to tell you -- his breaking ball is just not as sharp as it's been before," Gaston said. "He's not locating as well as he was, either."
The manager added that "there's a good chance" Downs has not yet regained his form after spending three weeks on the disabled list and having a few days off during the All-Star break. His mechanics may still need some tinkering.
Gaston said that he may pitch Downs in a blowout game if the opportunity arises on the team's upcoming road trip, giving the closer a chance to get back on track when the game is not on the line.
"If that comes up, it might be a chance for him to do that," Gaston said. "I hope that somewhere on this road trip, we can do that."
Downs is not the only member of the Jays' bullpen who has struggled at times this season. Toronto's relief corps ranks sixth in the American League with a 3.96 ERA -- an entire run higher than the bullpen's league-leading 2.94 ERA in 2008.
Last season, though, the Jays' bullpen pitched the fewest innings in the AL. This year, the relievers' workload is the sixth highest in the league.
"I think it's got a lot to do with the starters this year. The starters haven't been carrying us into seventh and eighth innings," Gaston said. "Even though some of the guys don't come out and pitch, they're up and down in the bullpen."
Given that Toronto's rotation has been mostly made up of rookies all season -- ace Roy Halladay is the only non-rookie starter at the moment -- the bullpen's workload is not surprising.
Things don't look to get easier for the 'pen, as Gaston has to keep an eye on the rookies' innings to avoid overworking them and putting them at risk of injury.
Gaston said earlier in the season that he may have to go to a six-man rotation at some point to keep the rookies' innings totals down.
"Some of these kids, they're going to run out of innings, so we're going to have to back some guys up, probably," Gaston said. "We might even have to go with six starters sometimes."
"Ricky [Romero's] going to be OK for the rest of the season, but the other two kids ... could be done almost by the first of September," Gaston added, referring to left-handers Brett Cecil and Marc Rzepczynski.
"If we try to keep them from having so many innings by September, we might have a chance to use them in September."
Gaston said the team hoped to get Scott Richmond, who is rehabbing a right shoulder injury, back by Friday, and the Jays could go to a six-man rotation as early as the homestand beginning on Aug. 4.
Erika Gilbert is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.