Youkilis, who was placed on the DL last week, needs surgery to correct a herniated disc and will be out of action for 10-to-12 weeks, the team said.
The 34-year-old has had trouble overcoming his back issues this season, batting just .219 average with two home runs, seven doubles and eight RBI in 28 games.
Meanwhile, Teixeira -- who has played only 15 games this season due to a strained wrist tendon during -- will again have to rehabilitate the wrist during another stint on the shelf, the Yankees announced.
The slugger has managed just a .151 average with three homers and 12 RBI during his time in the lineup.
Pitcher Adam Warren and outfielder Zoilo Almonte were recalled from Class AAA Scranton/Wilkes-Barre while pitcher Chris Bootcheck was sent down.