Joe Perry rushed to hospital after performing with Billy Joel at MSG

Sources connected to Joe tell TMZ, he's been having "breathing issues for the last few weeks and it came to a head last night." We're told it involves congestion in the lungs.

Our sources say Joe is still in the hospital but "he's awake, doing well and could be released as early as Sunday afternoon."

Joe Perry was wheeled out of Madison Square Garden on a stretcher Saturday night after performing with Billy Joel.

Eyewitnesses tell TMZ, Joe had just finished "Walk This Way" with Billy Joel on stage and went back to his dressing room. A source connected with the concert tells TMZ, Joe collapsed and "looked terrible."