Given knows the performances of Guzan mean he can take nothing for granted ahead of Saturday's home clash with Everton.
Given said: "For me, it's been a frustrating time not to have been playing over the past few weeks. But I'm glad to be back out on the training pitch and I'm glad to be working to be match fit again.
"The hamstring feels great. I haven't had a hamstring problem in my life so it's a bit new to me, to be honest.
"I've recovered really well and had lots of good treatment and I don't feel anything now. I just need to sharpen up."