Glenn said the Vikings did a "great job" of getting him back on the field.
"But the two-a-days took a pounding on me," Glenn told the Pioneer Press. "That was all me. I wanted to get out there and fight for a job."
Glenn aggravated the left knee he had surgically repaired last year.Glenn will return to Houston, to rehab and spend time with his newborn son.
There are no current plans for another surgery, and his only focus now is getting his knee right.
"He’s the epitome of being a professional," Childress said of Glenn. "He was a great guy to have in our locker room, and I’m sorry to lose him."
The Vikings also injured/waived RB Wendell Mathis.
They filled those two spots with linebackers George Hall and Cameron Siskowic.
At practice, LB John Kerr and CB Chad Johnson are the only ones absent. Johnson was excused to attend to a personal matter.
* DT Fred Evans will likely play Friday against the New York Jets. But defensive ends Erasmus James and Khreem Smith are not as certain.
"I'm more inclined to say let's wait another week," Childress said of James.
* G Adam O’Connor will get a second opinion on his injured left knee. But he appears to be out for several weeks.* QB Tarvaris Jackson made a poor decision when he was flushed out of the pocket. He tried to force a pass down the field, over a defensive back. But the ball was flat, and Tank Williams easily picked the pass off.
* The best defensive play belonged to Marcus McCauley and Patrick Body. McCauley was closing, defending rookie WR Sidney Rice. In the end zone, Rice bobbled the ball, with McCauley all over him, and Body slid over and intercepted the ball.
* Starting right tackle Ryan Cook got some snaps at center, while right guard Artis Hicks got more work at left tackle.
* Brooks Bollinger spent some time handling snaps for kicker Ryan Longwell. Bollinger is the backup holder to Chris Kluwe.