The Padres haven't named their Opening Day starter, but Edinson Volquez -- who started Opening Day last season -- figures to be a favorite. Clayton Richard, Jason Marquis and Eric Stults are a part of the rotation as well.
There are several candidates in camp in the running for the No. 5 spot, including Tyson Ross, who takes his 11 1/3 scoreless innings streak into Friday's game against the Mariners.
Andrew Cashner merits strong consideration, though getting him stretched out to a point where he can throw 90 or so pitches during the first week of the season might be tough. Cashner had surgery in December to repair a lacerated tendon in his right thumb.
Two other pitchers in camp on Minor League deals -- Tim Stauffer and Freddy Garcia -- are also being considered.
So could the Padres be in the market for a pitcher?
"Our scouts are out there, and we're talking to a few clubs," Padres general manager Josh Byrnes said. "But it's got to make sense for us. The guys we have, the depth and the long-term guys ... if it was someone we felt was an upgrade, we should take a look at it.
"But not to add a body for sake of adding pitchers."
During the offseason, Byrnes identified the corner-infield spots and the bullpen as areas of depth, and it's believed teams have asked about relievers Luke Gregerson and closer Huston Street.
Porcello, the 27th overall Draft pick in 2007, is 48-42 with a 4.55 ERA over his first four seasons with the Tigers. He will make $5.1 million this season.
Corey Brock is a reporter for MLB.com. Keep track of @FollowThePadres on Twitter. This story was not subject to the approval of Major League Baseball or its clubs.