Wolf threw 49 pitches over two innings on Wednesday against the Mariners and would most likely not have been available on Friday night. He is 1-3 with a 4.14 ERA in three starts and 18 relief appearances for the Rangers this season.
"Both guys have done a nice job when they've been here," Daniels said. "This gives us a chance to get an extra left-hander here this weekend."
Because Wolf was optioned, he cannot be recalled on Sunday when the rosters are expanded. He would normally have to wait 10 days, but he can come up on Tuesday because Round Rock's season is over.
T.R. Sullivan is a reporter for MLB.com. Read his blog, Postcards from Elysian Fields, and follow him on Twitter @Sullivan_Ranger. This story was not subject to the approval of Major League Baseball or its clubs.