Though the contract doesn't include a Major League component, Dombrowski said he has discussed "parameters" of a big league deal with Valverde's agent, Scott Boras.
Valverde will report to the team's extended Spring Training program in Lakeland, Fla., and throw to hitters before joining Triple-A Toledo. What happens from there, at this point, is anyone's guess.
If Valverde is throwing as well as Boras has said, both with a mid-90s fastball and a splitter he seemingly lost from his arsenal last year, then it's possible Valverde could regain the job he lost last postseason following blown saves in Oakland and at Yankee Stadium.
"We're not looking to prolong this," Dombrowski said. "It's a situation where he can either pitch and come back and help us here, or we probably end that relationship at that time."
The deal was announced a day after the Twins rallied for two runs in the ninth off Joaquin Benoit and Phil Coke to beat the Tigers at Target Field. While Dombrowski said he got a text from an agent for another free-agent reliever within a minute after that game ended, he indicated the Valverde deal came together Thursday morning after Valverde agreed to take a Minor League contract with no Major League guarantees.
"It's a situation where he really has never been willing to take this scenario, to say, 'OK, let him show you that he can do the job for you. We think he's throwing the ball better,'" Dombrowski said. "OK, let's see what it is."
Valverde saved 110 games over three seasons for the Tigers, including a franchise-record 49 in as many opportunities in 2011. He racked up 35 saves for Detroit last year, but he lost his role after back-to-back blown saves in the postseason -- first in Game 4 of the American League Division Series at Oakland, then again in the opener of the AL Championship Series at Yankee Stadium.
Dombrowski said at season's end that the Tigers would not re-sign Valverde, instead giving rookie Bruce Rondon a chance to compete for the closer job with Detroit's other relievers. While Boras argued at different points during the offseason that it's difficult for contending teams to turn to young closers with no Major League experience, the Tigers stuck to their plan.
When a report online in Spring Training suggested Leyland was pushing for the Tigers to re-sign Valverde, Leyland said that was not the case. As recently as a week ago, when the Tigers optioned Rondon to Triple-A Toledo, a reunion with Valverde was characterized as unlikely.
Commitment or not, the signing at the very least presents the Tigers with another option, either as a set closer or as part of a committee, though Dombrowski admitted Valverde feeds off the ninth inning for adrenaline.
"From my position, you don't leave any stone unturned," Dombrowski said. "You do whatever you can to make your club better. We do not have a dominant closer and most clubs that have a chance to win have a closer. That doesn't mean you can't win by mixing and matching either, but right now we're in a situation where we're mixing and matching and if the situation ends up being better with Papa Grande, with Rondon, with whomever it may during times, we're open-minded to that."
Valverde, who turned 35 on March 24, has been throwing near his home in the Dominican Republic, where a Tigers scout watched him throw a bullpen session last Saturday. Boras told MLB.com last week that Valverde was throwing 93-94 mph, and Dombrowski said Thursday that Valverde was throwing in the low to mid-90s.
"We wanted to see [the split]. We wanted to see what his velocity was," Dombrowski said. "They have told us his velocity has been up. It was maybe a tick up, just throwing on the side. He was throwing in the low to touching mid-90s and throwing some splits on a much more consistent basis.
"There's no question he has lost more weight, but that really was not a concern of ours last year because we thought he was in decent shape. But he has lost another 15 pounds, they've said, and our guys verified that he was in very good shape."
Whether that results in the stuff that made Valverde so effective -- and whether it changes the Tigers' stance on their bullpen -- remains to be seen. Whatever happens, it'll likely be eventful.