They also released Doug Mirabelli, who had been the personal catcher for knuckleballer Tim Wakefield, and sent five players to the minors. Moving Schilling to the disabled list cleared space for Boston to sign right-hander Lincoln Holdzkom to its 40-man roster.
The moves left the Red Sox with 40 players, including Schilling, in their major league camp six days before they leave for Tokyo, where they're scheduled to play two exhibition games against Japanese teams and two regular season games against the Oakland Athletics.
Schilling has said he would have preferred surgery, but the team insisted he try rehab. The right-hander said he wasn't hurt when he signed a one-year, $8 million contract with the Red Sox in November.
Mirabelli was placed on unconditional waivers despite his ability to handle the knuckleball. The skill Kevin Cash showed in catching Wakefield last year makes him the likely replacement for the 37-year-old Mirabelli.
Mirabelli hit a career-high .281 in 2004 when Boston won its first World Series title in 86 years. But he batted just .191 in 2006 and .202 last season.
"The staff felt pretty strongly that Cash was prepared to do a better job and that led to the tough decision today to let Doug go," general manager Theo Epstein said. "He's done a lot for this franchise over the years even though its been in a backup role. He's probably had an impact that exceeded the role and certainly contributed to two championship clubs."
Cash batted .111 in 12 games with Boston last year.
"There's no denying how special Dougie is with Wake," manager Terry Francona said, "and we certainly talked to Wake after this also because it's an important facet of what's going on, but there's other things to consider" besides catching a knuckler.
Holdzkom, who played in the Red Sox farm system last year, was selected in the Rule 5 draft in December by Philadelphia, then offered back to the Red Sox. Because it was his second outright assignment, he became a free agent and re-signed with Boston.
The Red Sox optioned right-hander Devern Hansack and outfielder Jonathan Van Every to Triple-A Pawtucket and assigned right-hander Lee Gronkiewicz and left-handers Jon Switzer and Michael Tejera to their minor league camp.