Benoit, a 36-year-old right-hander, will earn a guaranteed $15.5 million over the next two seasons -- $6 million in 2014 and $8 million in '15. The deal also includes an $8 million option for '16 -- which will kick in if Benoit finishes 55 or more games in '15 -- or a $1.5 million buyout.
The deal was first reported as done, pending a physical, on Dec. 18. The Padres and Benoit's agent have had discussions about a deal going back to the Winter Meetings earlier this month.
As for Benoit, the Padres feel they've landed a top-notch reliever who continues to get better with age, one who will handle the eighth inning in setting up closer Huston Street.
"He's obviously a late bloomer. He's had four good years in a row. Relievers hold up through advanced age, hopefully he can continue," Padres general manager Josh Byrnes said. "He has a fastball and a devastating change. He doesn't rely on his fastball to get his outs. He pitches to both sides of the plate. That was one of the things that made him attractive to us."
Benoit spent the last three seasons with the Tigers, compiling a 2.89 ERA over 205 games. He had a 2.01 ERA in 66 games last season with 24 saves. Since missing the 2009 season after having surgery on his rotator cuff, Benoit has a 2.53 ERA and a 164 ERA+ over that span.
The Padres looked at other free-agent relievers, but several indicated that they wanted the chance to close. The Padres, with Street, didn't need a closer. But Benoit, Byrnes said, liked the situation with the Padres.
"We were looking for a quality guy who has shown he can pitch effectively in these [late-game, high-leverage] situations. He embraced that and embraced coming here," Byrnes said. "For a guy who has been in the postseason four years in a row, he believes he can help us take our next steps as a team."
As for Portillo, the right-hander was originally signed by the Padres as a non-drafted free agent on July 2, 2008. Over parts of five Minor League seasons in the Padres organization, he compiled a 14-38 record with a 4.86 ERA. He was limited to 9 1/3 innings in 2013 due to triceps tenderness and a strained lat muscle.
"There's some upside to him, but he hasn't made up enough ground toward the upside," Byrnes said. "He hasn't had success above [Class] A ball yet. He still might. But right now, he has the greater distance to the Major Leagues of guys on the 40-man roster."
The Padres will have Benoit handle the eighth inning, but this deal also gives the club coverage in the ninth, especially since Street has landed on the disabled list three times in the past two seasons.
Benoit also gives the Padres coverage at the back end of the bullpen in 2015, as the team holds a $7 million club option on Street in '15.
So who will close for the Padres in 2015?
"We have given ourselves two good choices," Byrnes said.
The Padres have certainly been busy this offseason.
Earlier, the team signed free-agent starting pitcher Josh Johnson to a one-year contract worth $8 million. That came before the trade that landed outfielder Seth Smith from the A's for reliever Luke Gregerson.
The Padres also added a left-handed reliever, Patrick Schuster, in the Rule 5 Draft.
The bullpen arrangement is clearer with the signing of Benoit, as the Padres could use Dale Thayer or Nick Vincent to handle the seventh inning. The team still might add a left-handed reliever, even with adding Schuster, who must remain on the Major League roster all season or be offered back to the D-backs.
"We're still looking," Byrnes said. "Schuster will be given a look. [Cory] Luebke maybe pitches a little there to get acclimated again. But we'd still like to add another guy or two."
Luebke missed all of last season while working his way back from Tommy John surgery on his left elbow on May 23, 2012.