Hi Andy,
How is your calf coming along?
I just caught up with this post so hopefully you're well on your way to recovery, but I thought I'd reply anyway...
I think you need to give us a little more info on the injury, for example
1) Did your pain come on in one instant, for example an acute muscle tear, or did it get worse over time with a minor or no initial incident?
2) Which leg is it - the leg you would normally kick with or the leg you would normally balance on when kicking? (yes I know there are some freaks that can kick accurately with both legs, unfortunately not me!)
3) Do you have any knee pain or history of knee problems?
4) You seem to have ruled out DVT because the symptoms are different from the previous episodes, but are you sure? Given you have had it twice before, it is definately worth fully investigating.
You seem to have tested it quite thouroughly before going back to sport so we need to ask why did it come back when you played. Was it straight away (i.e. as soon as you started "kicking around") or after some time playing? i.e. is this problem related to a specific football related skill (kicking, rapidly changing direction, acceleration/decelleration etc) or a physiological demand (e.g. time under load, intensity of game compared to intensity of training etc).
If you're still having problems, then I think these questions have to be answered...
Cheers.
BMC