PEORIA, Ariz. -- Padres left-hander Christian Friedrich has been diagnosed with a mild left lat strain, ruling him out for the Opening Day roster.
The 29-year-old southpaw, who led the team in starts last season, hasn't pitched since March 17 and won't resume throwing for another week or two, according to manager Andy Green.

Friedrich's absence leaves three candidates -- Trevor Cahill, Jarred Cosart and Luis Perdomo -- fighting for two spots in San Diego's starting rotation. If Perdomo misses out, he'd open the year at Triple-A El Paso, Green said.
Meanwhile, neither Cahill nor Cosart can be sent freely to the Minors: Cosart is out of options, and Cahill signed a Major League deal during the offseason. But that doesn't necessarily rule Perdomo out of the mix.
"Right now, we have Perdomo, Cahill and Cosart battling it out for those last couple spots in the rotation," Green said. "If it's Cahill and Cosart, Perdomo would not go to the 'pen. He would go to Triple-A. The other guys would fall to the 'pen."
As for Friedrich, he's also an option to pitch in both the rotation and the bullpen. In a career-high 129 1/3 innings, he posted a 4.80 ERA last season -- his first as a full-time starter since 2012.
When he's ready to get back on the mound, the Padres will treat Friedrich's recovery process as that of a starter -- even if their plan is to ultimately use him out of the bullpen.
"Our first inclination would be to lengthen him out, at least to a certain set number of innings," Green said. "You never want to say exactly what you're going to do in the middle of April, because situations and context changes so rapidly. ... Both [starting and relieving] are open for us."