The forward broke a metatarsal in the Whites' 3-0 defeat of Bolton Wanderers at the Reebok in early April and was subsequently ruled out for the remainder of the 2011/12 campaign.
"There's never a good time to be injured, but I felt like I was playing well at that point and showing what I could do," Ruiz told fulhamfc.com. "To be injured in your first season at a club is also difficult and it was hard watching the team see the season through - I just wanted to be out there with them.
"All I wanted to do was get back quickly and, in working hard, fortunately I have managed to do that and I returned just in time for pre-season which was good. It feels great to be back and to be out on the pitch against Kaiserslautern last Saturday was brilliant.