I didn't play tennis for 1 week and I played yesterday and got two blisters (the "water" type) on my hand. I typically play 2-4 times a week. I don't get it. Now I can't play and I can't figure out how I could get blisters after only taking a week off. I've never had a problem with blisters and I have taken a week or so off during the past few years. Ideas?