Chris Perez, the hard-throwing 23-year-old, inherits Wood's closing duties in the short term.
Informed by reporters of the staff's decision to turn to him, Perez said, "It's a great opportunity. I won't lie. I only hope it would've come under different circumstances."
Wood will open the season on the disabled list -- marking the 13th stint of his 12-year career on the list.
Cleveland general manager Mark Shapiro called the news "disappointing" and a "challenge we will get through."
"You expect challenges every spring, and this is the first one we've come across," Shapiro said. "It's disappointing, because we thought we were set with Kerry, who was such a dominant guy the second half of the season."
Wood had an ERA of 2.96 in 24 appearances after the All-Star Game last year.
He last pitched in a Cactus League game on March 10, when he retired all three Padres batters he faced but reported increased soreness the following day.
2010 Spring Training - null
Sights & Sounds
Spring Training Info
Soloff categorized the latissimus muscle as "a principal accelerator of the arm."
"It's an area in which he usually experiences soreness during Spring Training," said Soloff, pointing to the rear of his right armpit. "After four, five days the symptoms did not recede, so we did the tests.
"The good news is, it's nothing structural. That's the positive -- it's not the elbow or the shoulder, which have been surgical issues in the past. If you were to ask Kerry, he'd tell you he's had something like this the last four, five Spring Trainings."
During his star-crossed career, the first nine years in the Cubs' starting rotation, Wood has served time on the DL with elbow, shoulder, oblique muscle and triceps injuries, plus a blister on his finger.
After transitioning to the back end of the bullpen as a means of easing the burden on his arm, Wood logged 54 saves in two seasons with the Cubs and with the Indians.
Wood wasn't at the Indians' Spring Training complex, where he had been rarely spotted since he cancelled his scheduled appearance a week ago after warming up in the bullpen.
"In the short term, we'll focus on the inflammation in the area, looking for reduction," Soloff said.
Shapiro asserted he would not hit the market in search of a veteran closer to step into Wood's shoes.
"[Wood's absence] won't be such a long time," Shapiro said, "and we feel Chris can handle the job in the interim. It will be an opportunity for him."
Manager Manny Acta has the benefit of the last two weeks of Spring Training to ease Perez into the role. Perez has made five one-inning scoreless appearances in Cactus League play, allowing a total of two hits, with three walks and four strikeouts.
"But it's never a good time to lose someone like Kerry Wood," said Acta, who expressed enthusiasm for Perez's ability to handle the pressure-packed role, especially mentally.
"He's got the solid makeup to do it. He's the type who can blow off the bad games," Acta said. "The kid has always dreamed of being a closer, and now he gets his opportunity."
Perez, who has struck out 110 in 98 2/3 innings in his first two Major League seasons, feels that having hung around some premier closers during his young career has prepared him for the task.
The Indians acquired him last summer in the Mark DeRosa deal from the Cardinals, with whom Perez had earned seven saves in 2008. A first-round choice of St. Louis in the '06 First-Year Player Draft, Perez apprenticed at the elbows of Jason Isringhausen and Ryan Franklin.
"What I learned from them is that the big thing is the mentality," Perez said. "Everyone has the [physical] tools, but you have to believe in yourself to do it.
"This will be a good audition," Perez continued. "But it's not a good situation for the team. It's a big blow. Hopefully [the prognosis] is wrong, and Kerry will be back sooner, and I can get back to being the eighth-inning guy."