"It's probably the smart decision, I think," said Smith, the 12th Angels player to land on the DL this season. "But it still [stinks], either way."
Young right-handed reliever Mike Morin, sent down after he posted a 5.48 ERA in 25 appearances, was recalled from Triple-A Salt Lake to fill Smith's spot on the roster. To make room for Tuesday starter David Huff -- on the active roster and the 40-man roster -- Javy Guerra was designated for assignment for the second time this season.
Smith began to feel discomfort in his left hamstring during an outing at Dodger Stadium on May 19. The Angels' closer, Huston Street, was on the DL at the time, so Smith was determined to pitch through it, "But it just wouldn't go away," he said.
"You go out and throw a baseball, and if your lower half isn't right, something's going to happen up top," Smith added. "You can usually get through it for a little bit if you're able to, but ultimately it's just too much. For just too long, I couldn't get it out."
Smith allowed eight baserunners over a 4 1/3-inning stretch in his last five appearances. He was basically unavailable during a home series against the Tigers a week ago. And though he pitched a scoreless inning in Pittsburgh on Saturday, Smith had to work around two walks and a hit batter.
Angels manager Mike Scioscia finally revealed Smith's hamstring injury after that game.
He stayed away from using him on Sunday and Monday, then placed him on the DL on Tuesday.
"He thought he could still pitch," Scioscia said of Smith, "but he's really putting all the stress on his arm, and it's just going to be a matter of time before it compromises his health there. We hope that by just pulling him back, and shutting him down for a couple of weeks, it will get him where he needs to be."
Alden Gonzalez has covered the Angels for MLB.com since 2012. Follow him on Twitter and Facebook, and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.