Matteo played in Tuesday's crucial 2-0 win against Fulham in an effort to help dismiss any worries Leeds had of an end-of-season relegation battle.
"My knees aren't too good but I knew how important the game was for the club on Tuesday and there was no way I was going to miss it," he told the club's official website.
"The lads were all saying 'come on' and that's great, but if I'm being honest I could hardly walk on Saturday after the game.
"I've already had an exploratory op and had it cleaned out, but it's still affecting me and it needs sorting."