Whitehead was thrilled to put his cruciate ligament hell behind him last night, getting an hour's competitive play in Andy Lawrie's testimonial game in Falkirk before he was withdrawn as a precaution.
The midfielder told the Sunderland Echo: "It was great to be back. The cold wasn't really a factor - not once you've warmed up before the game. It was just nice to be back out there playing again.
"There hasn't been any reaction so far in the knee but I didn't really expect there to be any. The knee is fine at the moment and it feels good, I just need to work on my fitness now."
Whitehead could have continued but Keane was always going to be cautious with him.
The midfielder said: "The plan was always for me to play an hour, even if I felt like I could go on for longer. It was the right decision because when you get a little bit tired there is always the chance that you can miss-time challenges and that certainly wouldn't have helped my recovery.
"I've been looking forward to making my comeback for a little while now and it's just good to have come through it OK. Maybe I will be involved in another game next week, we'll just have to see."