Already unlikely to be ready to pitch when the Los Angeles Angels' season starts next month, C.J. Wilson's timeline for returning to the mound is up in the air. The veteran lefty experienced discomfort in the shoulder that has been bothering him when he threw a bullpen session over the weekend.

Angels manager Mike Scioscia admitted Monday the setback makes Wilson's estimated return hard to predict. After undergoing procedures in the offseason for his elbow, Wilson has yet to face batters during spring training this month and now has to go back a step in rehabbing his shoulder.

"Probably back him off from the mound until he feels like he's ready to take that next step," Scioscia said, noting that Wilson would try to throw on flat ground this week. "He's coming along a little slower."

Meanwhile, veteran right-hander Jered Weaver will visit a neck specialist after being diagnosed with "mild degenerative changes in his cervical spine." Weaver pitched against the Los Angeles Dodgers Wednesday and gave up three home runs while only reaching 81 mph with his fastball.

Weaver was already dealing with a loss of velocity as he logged more mileage on his arm, but a fastball losing that much is truly alarming. The Angels believe the diagnosis is not as severe as it sounds, but Weaver indicated the "tension" he felt in his neck was causing him "to not be able to throw the ball like I want to."

Wilson and Weaver are likely to start the season on the disabled list, and lefty starter Tyler Skaggs will as well. However, Skaggs is coming back from Tommy John surgery and his outlook for the 2016 season is far more positive. Skaggs threw live batting practice on Monday, and there did not appear to be any cause for concern.

Garrett Richards will likely take the ball for the Angels on opening day and will be followed in the rotation by Andrew Heaney, Hector Santiago, Matt Shoemaker and Nick Tropeano. Richards has the Angels excited to see what he can do this season. In 2-2/3 innings in last week's start against the Arizona Diamondbacks, the righty hit 100 mph with his fastball twice and came one mph short of triple digits four times.