Before getting hurt, Downs posted an ERA of 1.98 in 26 appearances, but that figure rose to 3.41 between his first and second trips to the DL. He went 0-3 over that span, with two blown saves and seven earned runs allowed in seven innings.
Gaston was not prepared to say whether or not Downs would once again be the team's closer once he is activated.
"He goes right back to the bullpen," Gaston said. "I'm not sure about closing. I'm not sure about that. We'll see how it goes. If he got here tomorrow and I said we're going to stick him in the closer's spot right away, I'm not sure if that's fair to him either.
"We'll see who's hitting. We'll see what numbers we've got on guys and see if it's a possibility for him to do that."
Downs was named the team's closer after former stopper B.J. Ryan struggled out of the gate this season. Ryan was subsequently released by the Jays on July 8.
Right-hander Jason Frasor has taken on closing duties since Downs' injury. While some combination of Frasor and Downs will likely fill the role for the rest of the year, the closing situation beyond this season is still up in the air.
Gaston was not willing to say that Downs would be the team's closer in Spring Training, since the southpaw has not had much of a chance to show he can do the job.
"Downs did great as a setup man, but he hasn't really had the opportunity to show us that one way or the other -- not much," Gaston said. "He's had a couple of times out there that didn't work out, but as far as really showing us that he's the guy, he hasn't had the opportunity because he's been hurt."
Gaston added that the scuffling Jays have given Downs few save opportunities to work with when he was healthy. He also pointed out that no one else in the bullpen has made a strong bid at the job this season.
"I don't see anybody else right now for that job," Gaston said. "Of course, the season's not over. Maybe somebody will step up and show something different."
For Gaston, assigning the role in Spring Training is difficult, since pitchers on the Major League roster usually aren't pitching in save situations.
"To say, 'Who's your closer?' and to try to see which one does a better job in Spring Training is a little tough to do," Gaston said. "How do you work on that in Spring Training? Usually those guys, they don't stay around to pitch the last inning in Spring Training. They pitch early in the games sometimes."
It's even harder to say who the closer will be beyond 2010, as both Downs and Frasor are set to become free agents after next season.
Down the line, Gaston is looking for a stopper who can pitch effectively against both right-handed and left-handed batters, rather than a left-handed or right-handed specialist.
"I think closers are like [Mariano] Rivera -- he gets everybody out pretty much," Gaston said.
"When you really say a guy is a closer, he gets everybody out. That's really a closer."