Holland says it was a "freak accident at home" that resulted in him falling on his stairs and needing surgery on his left knee.
Holland was being counted on to be the Rangers' #2 starter this season. There were discussions that Alexi Ogando might return to the bullpen, but this injury would seem to suggest that Ogando will, more likely than not, start the season in the rotation. If Colby Lewis, who is in camp on a minor league deal, is not able to fill the #5 spot in the rotation, the Rangers would be looking at someone like Nick Tepesch to round out the rotation behind Yu Darvish, Matt Harrison and Martin Perez.
The link above includes the following quote from Jon Daniels:
"This is an opportunity for a number of our guys," Daniels said. "Whether it’s Robbie Ross or Michael Kirkman or Tanner Scheppers or Nick Tepesch … opportunities for those guys to step up and seek the opportunity.
"It’s not good news, but we look at it as an opportunity for some other guys to seize that chance."
This is obviously bad news for the Rangers, while Daniels says the Rangers will look to fill the spot internally, you have to wonder if this might have them re-considering whether they might want to get involved in the free agent pitching market, particularly given their long-standing interest in Masahiro Tanaka.