WALTHAM, Mass. -- Celtics swingman Jeff Green, re-signed to a one-year, $9 million deal this past weekend, missed his fourth straight practice Monday after the team discovered something of concern during his physical.

Celtics president of basketball operations Danny Ainge stressed Monday that it's not something of major concern, and certainly not something that would immediately threaten the deal, but he did note that Green would likely be sidelined for a couple more days.

Green, who had been present at Boston's sessions the past couple days and shot on the floor after the sessions, was not spotted during the portion open to the media on Monday.

"We found something in the physical that we anticipate is fine," said Ainge. "We just have to be real cautious."

Pressed on a timeframe, Ainge added; "I don’t think very long. He’s just going through the tests again, today and tomorrow, and he should be fine."

Asked if it was something that could nullify the pact, Ainge again stressed it was merely precautionary.

"No, no," he said. "We’re not even close to that yet. It’s just precautionary. Practice just started today, really -- officially, when we had our whole team here -- so it’ll be resolved this week."

Celtics coach Doc Rivers suggested that he had no other information on the situation and had simply been told that Green would be absent at the start of the week.

"I really don’t know," said Rivers. "They’re still doing tests and all that kind of stuff. Honestly, I didn’t ask Danny [for an update on Monday]. I knew it already, that he wasn’t going to be here, so I didn’t give it a lot of thought... Danny told me don’t expect him the next couple days."

The Celtics acquired Green, Nenad Krstic, and a 2012 first-round pick in a deadline deal with the Oklahoma City Thunder that sent out Kendrick Perkins and Nate Robinson. Green was a restricted free agent after the 2010-11 season and Boston initially extended a one-year, $5.9 million qualifying offer before agreeing to the deal that featured a healthy salary bump.

Green's name had been mentioned in potential trade scenarios when the Celtics were exploring trade options for New Orleans point guard Chris Paul.