The right-hander, who was placed on the 15-day disabled list Monday for the second time this season, felt some discomfort on his first pitch to the Reds' Joey Votto in the ninth inning Sunday. That was the reliever's second inning of work, and Votto was the seventh batter he faced in the game.
"I was definitely disappointed," Fujikawa said about getting the MRI results. "I gave it my all, and I don't have any regrets."
Fujikawa compiled a 12.46 ERA in five games in April before going on the DL April 13-May 10 because of a strained right forearm. When he returned, he looked much sharper and had given up one earned run over 7 2/3 innings in seven games for a 1.17 ERA. Sunday's game was his seventh appearance since coming off the DL.
Cubs general manager Jed Hoyer got the news Tuesday night, and said the MRI revealed a rupture of the UCL in the right elbow.
"We're disappointed, obviously," Hoyer said. "Whenever we start talking about forearms, it concerns you. We were cautiously optimistic, because the physical exam was positive. The thing about him saying he felt a 'pop,' to be candid, we were hoping it might be something that was lost in translation. Obviously, he was right."
The Cubs had MRIs of Fujikawa's arm before they signed him last Dec. 7, and he was healthy.
"This was something that happened the other day," Hoyer said. "It's the nature of pitching."
Fujikawa has a 5.25 ERA in 12 games this season, giving up seven runs over 12 innings. This is the right-hander's first season in the Major Leagues.
"When healthy and coming back from the DL, I gained confidence that I was able to pitch against these guys at the big league level," Fujikawa said through interpreter Ryo Shinkawa. "Being a pitcher, this [injury] is a possibility for anybody out there, and it happened to me this time."
The Cubs and Fujikawa have not set a date for the surgery, nor have they picked a doctor. The pitcher was expected to have the procedure done in the U.S. The righty said he is confident he can come back and contribute to the Cubs.
"The message [from the Cubs] was, 'We want you to come back stronger,'" Fujikawa said of his talk with team officials. "I think this surgery has a high success rate. I believe in that, and I'm sure it'll be a long process for the rehab, but I'll work through it and try to come back strong."
The rehab can be a little shorter for a relief pitcher than a starter, but Hoyer said the Cubs will have a better idea about that once Fujikawa has the surgery and begins his comeback.
"We've been pretty conservative building him back [since his first time on the DL] and hadn't pushed him to go two innings yet," Hoyer said. "He was throwing the ball well and his walk-to-strikeout ratio was impressive. I feel the guy we saw at the beginning of the year wasn't him. He's a guy who has good command of his fastball, and when that didn't happen, something was wrong.
"The guy we've seen since he came off the DL was more of what we were expecting," Hoyer said. "The timing is disappointing, and we're confident we'll get a very good pitcher back next year."
Fujikawa had taken over the closer's role after the first week of the season, but lost that job when he went on the DL the first time.