As Ricky Romero struggled through his disastrous 2012 season, it was often speculated he must have been hurt. Now we know he was.

The Blue Jays' 27-year-old left-hander had arthroscopic surgery two weeks ago to "clean up" scar tissue that had built up in his left elbow, he and the club announced Tuesday.

Romero admitted he pitched through an unusual soreness on the outside of his elbow through most of the season, but said he wasn't sure if it caused his poor performance.

"Did it have any impact? I will never know, but I'm not going to make any excuses about the bad year," he said in a conference call with reporters. "… I stunk and that's it."

Although Romero was one of the club's few pitchers to avoid a stint on the disabled list this year, the Jays' Opening Day starter and former all-star endured the worst season of his young career. He posted the highest earned run average in the majors among qualified starters, while setting career-worst marks in nearly every statistical category.

His dramatic drop in performance from a year ago — his ERA increased by nearly three runs — confounded the organization and the team's fans, leading many to wonder if a lingering injury was holding him back.

But the native of East L.A., known for his bulldog mentality, never missed a start — except when he was skipped for poor performance— and both he and the club insisted throughout the year he was not hurt.

"I felt like with rest — you know, me just trying to be my own doctor — I was like, 'I'm sure with rest I'm going to be fine,'" Romero said, adding that he received regular maintenance treatment throughout the year and "battled through" the pain.