CLEARWATER, Fla. -- St. Patrick’s Day in Clearwater is a holiday upon a holiday with Phillies fans clad in green.

It seemed like a good day for Bryce Harper to play, especially considering he had not played since Thursday. But Harper missed his third consecutive Grapefruit League game on Sunday, and Phillies manager Rob Thomson said he will miss his fourth on Monday. Harper is experiencing stiffness in his back, according to Thomson.

“I’ve backed him off,” Thomson said after the Phillies' 5-5 tie with the Blue Jays at BayCare Ballpark. “He’s been doing a lot of work. A lot of swings, a lot of defensive work. He got a little stiff, so we’re just being precautious. We’ll just back him off for a few days.”

His level of concern?

“None,” Thomson said. “Zero.”

Thomson said Harper will be back in the lineup “for sure” by the end of the week and that he will be ready for Opening Day.

“I don’t have any concern at all,” Thomson said.

Harper has had back issues in the past, although he has never been placed on the injured list because of them. Last season, the 31-year-old Harper experienced mid-back spasms early in an Aug. 10 game against Washington. He left that game, then missed the next day’s contest before returning to action. Harper started 14 of the next 20 games at DH before returning to regular action at first base on Sept. 5.