If I were Rooney's personal advisor, this is what I would advise:
The day after the season is over, take a 2 week break from all football activity, hopping from tropical island to tropical island and doing things to Colleen that cannot be discussed in front of polite company. Eat well (as in healthy, not some of the crap that passes for "food" in the UK) and get plenty of rest, but don't let yourself go. Maybe even read some books, whether historical fiction or Anne Rice novels, something to make the brain perform some basic functions.
After your 2 weeks are up you begin moderate conditioning for a few days at a secret Nike campground, just to wake the body up. Then go full bore with a Spartacus workout, shedding those extra 5-8 pounds that you've been carrying the last few years. You want to see muscle definition in your abs, delts, thighs, maybe even some veins popping out of your neck and calves.
Now that you've gotten yourself into proper condition for a footballer you're ready to go into pre-season training, in full seek-and-destroy mode when the season begins.
Do the conditioning, Wayne, and your natural ability will carry you far. Very far.