Saunders allowed five runs on five hits over just 1 2/3 innings and landed on the 15-day disabled list after the game with stiffness in his left shoulder.
Furthermore, his troubles against the Rangers put the Angels in a deep hole they couldn't recover from in an 11-6 loss in front of 43,624 at Angel Stadium.
But for Saunders, it was finally time to throw in the towel and head to the disabled list after struggling to the tune of a 5.33 ERA this season after setting a career-best with a 3.41 ERA last year.
"I've never wanted to be taken out," Saunders said. "I've never been the one to say I can't pitch. But it's just time because it's hurting the team and that's the last I thing I want to do."
Saunders said there is a knot in his left shoulder that has plagued him all season, which hasn't allowed him to fully extend on the mound.
"I've tried to pitch with it the whole year," Saunders said. "My shoulder hasn't been the same. It doesn't hurt but I just can't get extension and get out front."
Manager Mike Scioscia acknowledged that he knew about Saunders' shoulder problem, but said every player in the clubhouse "has something bothering them," but also said that Saunders' performance Friday night made the decision simple.
"It's tough but the decision is pretty easy when you evaluate the way Joe has pitched his past eight to 10 starts," Saunders said. "We have a little window here to get ready for September and hopefully he'll be where he needs to be and finish strong for us."
Saunders was roughed up in the first inning for four runs, including a three-run home run to Josh Hamilton and a solo shot to Hank Blalock one batter later. He then allowed another run in the second and hit a batter with two outs before being removed by Scioscia without showing any noticeable signs of discomfort at the time.
"I feel like I'm throwing the ball good," Saunders said of his Friday outing. "I'm getting behind guys but I'm not getting the breaks. I made one bad pitch tonight, a home run to Blalock, and I made a good pitch to Hamilton and he burned me. So I need to move on and clear my head and [get] some rest."
With Saunders' struggles, the Angels continued their woes against the Rangers this season, falling to 2-8 against their division rivals.
"They're a terrific ballclub," Scioscia said. "They're playing great baseball this year."
The Rangers blew the game open with three home runs in the fifth inning against reliever Justin Speier. Catcher Taylor Teagarden opened the frame with a high-arcing home run to left. After an Elvis Andrus groundout, Vizquel and Michael Young added back-to-back dingers.
The Angels, though, threatened in the seventh with four runs after loading the bases with no outs against starter Scott Feldman. Howard Kendrick grounded into a fielder's choice to plate one run before Maicer Izturis hit a three-run homer to bring the Angels to within three runs of the Rangers.
Kendry Morales had the chance to cut into the deficit with two runners on and two out, but popped up to shortstop against rookie Neftali Feliz, who was consistently hitting 99 mph on the radar gun.
The Rangers then added insurance runs in the eighth and ninth innings against reliever Shane Loux, who stretched out to pitch four innings, allowing two runs (one earned) on four hits.
The Angels added a run of their own in the ninth against former Angels reliever Darren O'Day, but Morales grounded out with two runners on to end the game.
"Those guys don't stop," Texas manager Ron Washington said of the Angels. "They keep coming at you. They never feel they are out of a ballgame. Our offense did a good job of adding on runs."
With the loss, the Angels are now just 3 1/2 games up on the Rangers with two more to go this weekend at Angel Stadium.
But the club will get some help for their bullpen as Jose Arredondo will be called up to replace Saunders on the active roster.
Arredondo was tremendous in 2008 with a 1.62 ERA, but struggled to start this season with a 5.55 ERA in 25 appearances. He was sent down to Triple-A Salt Lake where he was 1-1 with a 2.18 ERA in 20 games.
"Jose has been throwing the ball much better," Scioscia said. "He's cleaned some mechanical stuff up and has good stuff on his fastball again and a tremendous splitter so hopefully he'll come up and be better than he was to start the year."
Rhett Bollinger is a reporter for MLB.com This story was not subject to the approval of Major League Baseball or its clubs.