The determination to put him on the DL happened after Buchholz threw a bullpen session.
"Just felt a little bit in the knee today in the bullpen, and that's the reason I threw a bullpen [session] today instead of tomorrow, so the organization felt like it would be best to do a DL stint and get an added arm in the bullpen for the duration that I'm out and obviously for me to refine what I need to refine," said Buchholz.
The Red Sox already have one starting pitcher on the disabled list in Felix Doubront. Brandon Workman is filling his spot. Allen Webster would seem like a logical candidate to fill in for Buchholz on Saturday, but no announcement has been made yet.
Buchholz met with manager John Farrell and pitching coach Juan Nieves before the session to not only talk about his health, but his confidence on the hill so far this season.
"It's not at its peak," Farrell said. "That goes without saying. We continually work with him on that. Bottom line, it's in-game execution and adjustments."
Toward that end, Buchholz spoke with Bob Tewksbury, the former sports psychologist for the Red Sox who now works for the Players Association.
"He's a good asset to anybody now in baseball. Over the last couple of years, he was to our club and he's been through a lot," said Buchholz. "Anyone that can pitch as long as he can in the big leagues at 85 miles per hour has to have a good mental side of the game. He's a good guy to pick at and just ask him through the ups and downs that he went through, how he prepared and how he got through it -- and he obviously got through."
Buchholz, who's been hit hard in three of his past four starts, is 2-4 with a 7.02 ERA.
"Our history with him allows us a closer read on his metal state. It can't just be done through conversation," Farrell said. "It has to be through candidness and things that might be there. We are working through it right now."
"Probably going to take a couple of days off, doing nothing, just to let everything speed the recovery a little bit and then I'm sure I'll be getting in some bullpen [sessions] here in four or five days or so," said Buchholz.
The righty hopes to regain his form when he returns.
"It's not an injury to my arm like it was last year," Buchholz said. "First and foremost ... the ball is coming out of my hand fine. It's just a matter of getting that little fire that I had last year as far as throwing pitches in the zone and pitching to contact instead of pitching to swings and misses, and like I said, it's hard to do whenever you miss with the pitch. It seems as if every time you miss, it gets hit hard, so I gotta get back to the basics and go from top-to-bottom with it."
With Pawtucket this season, Wilson is 1-0 with five saves, and a 1.42 ERA in 18 appearances, all in relief. He has held opponents to a .182 batting average and is averaging 9.9 strikeouts per nine innings with the PawSox.
Last year, Wilson made his Major League debut with 26 games over three stints with the Red Sox, going 1-1 with a 4.88 ERA and 22 strikeouts with 14 walks.