I think 3 times a week would be a good frequency. As I believe it is good to train your HR at all levels of intensity, here are my suggestions:
1) once a week run at moderate and steady pace for 25 minutes, and spend the last 5 minutes running faster. For example, if you can run for 25 minutes at a 9:00/mile pace, run the last 5 minutes at an 8:00/mile or faster pace.
2) once a week, if you have access to hills do
hill sprints. Alternatively, you can substitute the hills with football stadium steps but I like hills better. Warm-up for 5 minutes, then do a 30 second max effort hill sprint, then walk down the hill for 2 minutes to recovery. You'll probably need the entire 2 minutes to recover if you hill sprint intensity is really max effort. Now complete a total of 8 rounds. The sprint part of this workout takes 20 minutes. Spend the last 5 minutes jogging for a cool-down.
3) once a week perform Tabata protocol sprints. Warm-up for 5 minutes, then perform max effort sprints on the track for 20 seconds, recover for a mere 10 seconds, then repeat for a total of 8 rounds. The sprint portion only takes 4 minutes, but it is 4 minutes in hell. Then spend another 5-15 minutes jogging to cool-down.
Since you are playing football, the hill sprints and Tabata sprints will help you tremendously with the explosiveness required of the game. And you'll be surprised at the contribution they will make to your
cardiovascular fitness and weight management goals.
As always, spend a quality 5-10 minutes after these workouts with some leg and lower body stretching.
You are at a higher risk of hamstring injury when doing sprints so be careful.
The hill sprints and Tabata sprints are very demanding. I cannot imagine that you would want to lift weights after you do these workouts.
I don't believe it is necessary for you to run 6 days a week if you put your max effort into these 3 days of running training.