O'Day, who wrote on his Facebook fan page earlier in the day that he was headed to the DL, is eligible to be activated June 27. This is his first stint on the list.
Surgery is scheduled to be performed Thursday by Tom Byrd in Nashville, where O'Day was examined Wednesday.
Rangers manager Ron Washington said O'Day had been pitching in pain for some time and it finally got to be too much.
O'Day, 28, pitched a scoreless ninth inning Tuesday, getting two ground-ball outs and a strikeout to go along with a seeing-eye base hit in a 10-3 loss to the Blue Jays. It was a much better showing than his previous outings this season.
But even after Tuesday's game, he seemed uncertain about how his hip would hold up.
"We're still working through it [the hip issues]," O'Day said. "We'll see what happens. We'll see how it responds. It feels fine now, but I don't know. But to get out there, throw strikes and get outs was important."
O'Day had struggled with his command and has four walks in 7 1/3 innings. He also has hit two batters. His left hip bothered him enough last weekend that Washington didn't use him at all during the series with the Kansas City Royals.
O'Day was one of the club's most consistent bullpen performers in 2009 and 2010. He was 2-1 with a 1.94 ERA in 55 2/3 innings in 2009 after being claimed off waivers from the New York Mets in late April.
Tucker is is 1-1 with a 4.09 ERA at Round Rock, but those numbers are inflated because of his first outing. In his past 7 2/3 innings of relief, Tucker has allowed one earned run on two hits with eight strikeouts and two walks.
The Rangers' bullpen remains a unit in constant flux this season, starting with Tommy Hunter's groin injury at the end of spring training that forced primary eighth-inning setup man Alexi Ogando to the starting rotation.
Injuries haven't helped the bullpen build any kind of continuity. Mason Tobin is on the 60-day disabled list (right ulnar collateral ligament inflammation) and closer Neftali Feliz was put on the 15-day DL because of right shoulder inflammation. He's eligible to return May 6, and the club said the move is precautionary.
Richard Durrett covers the Rangers for ESPNDallas.com. Information from Randy Jennings was used in this report.