Santos joined the Blue Jays with high expectations before the 2011 season. He was acquired to become a long-term option at the back end of Toronto's bullpen, but instead suffered through a seemingly endless list of injuries and control problems.
"He hasn't thrown well, clearly some guys are being used more than him right now and the only way to get out of this funk is to pitch," Blue Jays general manager Alex Anthopoulos said. "But it's hard to find a spot for him right now, certainly not a long guy, and he's not going to be used late in the game."
The roster move is yet another twist in what has been a tumultuous year for Santos. The 31-year-old thought he had been traded to the Rangers over the winter as part of a three-way deal that reportedly would have netted the Blue Jays left-handed starter Brett Anderson.
The trade eventually fell apart because of health concerns about another player, but not before Santos underwent a physical with his supposed new organization. Santos then remained in Toronto, and when Casey Janssen got hurt in the spring, Santos began the year as the Blue Jays' closer.
Santos struggled in that role and blew three save opportunities in the span of two weeks. He later hit the disabled list with a right elbow injury and has been stuck in limbo since. Santos clearly lost the trust of manager John Gibbons, and with his appearances coming few and far between, there was very little opportunity to find a groove.
Anthopoulos denied that Santos had requested a trade and also said "no" when asked if Toronto had explored possible deals with other teams.
"He's a very accountable guy, he knows he hasn't pitched to his ability," Anthopoulos said. "He knows he can be a dominant closer, setup guy, whatever is needed. Like anybody, he has all the belief in the world in himself, he'll be fine. He'll get it back, he has way too much talent.
"Stuff is still there, still striking out over a guy an inning. It's just command and once he can get ahead in the count, he's going to be back to being the guy he was. Hopefully it will be quick. We hope this is a quick move, get some innings, get hot and come back because we certainly could use the help."
One possible ripple effect from this move is that it could free up some money for the Blue Jays to use at the July 31 non-waiver Trade Deadline. There's a strong belief that the Blue Jays don't have a lot of cash at their disposal, but the loss of Santos would make the acquisition of another player with a similar salary structure possible.
The only way that can happen, though, is if another team claims Santos before Wednesday's deadline. That could be what the organization is hoping for, but at the moment, the club appears to want to get Santos into the Minors so he can return and make an impact later this year.
"I don't think Sergio, when he's right, is a middle reliever," Anthopoulos said. "We know he can close games, he has done it before, he has the ability to do that. The timeline, hopefully, is as soon as he can. As well as he does, we're going to look to get him back here. I can't stress that enough."
Left-hander Rob Rasmussen was recalled from Triple-A Buffalo to take Santos' spot on the 25-man roster. Rasmussen has appeared in seven games for the Blue Jays this year, allowing four earned runs in six innings while striking out seven. The 24-year-old has a 2.61 ERA in 25 games with Triple-A Buffalo.
Santos appeared in 24 games for Toronto this season, going 0-2 with five saves and a 7.78 ERA. Over three seasons, he made 59 relief appearances and went 1-4 with a 4.83 ERA and eight saves.