I feel your pain (literally). I just got back playing Soccer after about a 2 year layoff (kids, starting a business, friends quit playing, etc.).
The problem is I'm fit enough to run pretty hard for 90 minutes, but I'm not used to sprinting that long, so my hamstrings (especially knee flexors) are just getting abused. Just had game #4 Sunday, and I'm feeling a little better than the last few weeks--I'm cautiously optimistic that I'll be walking on Mondays in a few more weeks.