Craig is correct. If you include a future time (e.g., "tomorrow") then you do not need to add "will" to a verb. Examples: "I go to Budapest next week for the annual trade show." "I meet with our customer on Thursday to discuss the contract." "I get my hair cut on Saturday morning."

He will play football tomorrow is more grammatically correct, however you could hear either in common speech. You could also shorten 'He will' to He'll He'll play football tomorrow.