MESA, Ariz. -- The Angels don't necessarily have eight starters fighting for five spots on the Opening Day rotation.

It's basically down to six now.

Tyler Skaggs, easing his way back from Tommy John surgery, and C.J. Wilson, recovering from a brief bout with shoulder tendinitis, seem likely to begin the regular season on the disabled list, though the Angels are hopeful that they can be ready at some point in April.

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Wilson, who spent the week attending to his wife while she gave birth, returned to the team on Friday and played catch for the first time in 12 days. The 35-year-old left-hander underwent an elbow cleanup last August and experienced soreness in his shoulder during a bullpen session on Feb. 20, prompting an MRI that revealed what the club deemed mild tendinitis.

The Angels are being cautious with Wilson, who's still about 10 days from getting off a mound again, putting him well behind the other starting pitchers in camp.

Skaggs threw what Angels manager Mike Scioscia called a "tremendous" bullpen session on Friday, but it was also his first in about a week. The 24-year-old left-hander is more than 18 months removed from elbow ligament replacement surgery, but he wanted to be extra careful after experiencing some general soreness early in camp.

Skaggs will probably throw another bullpen session on Monday, then possibly throw to hitters in live batting practice a couple of days after that. But he probably won't appear in his first game until the middle of March, which isn't enough time to have the proper length required to begin a season.

The fact that Skaggs and Wilson were both recovering from elbow surgeries was a big reason the Angels were hesitant to part with any of their starting-pitching depth over the offseason. As it stands, Garrett Richards and Jered Weaver are seemingly the only healthy starters locked into a rotation spot. Andrew Heaney, Hector Santiago, Matt Shoemaker and Nick Tropeano are competing for the other three spots.

Alden Gonzalez is a reporter for MLB.com. Follow him on Twitter @Alden_Gonzalez and Facebook , and listen to his podcast.