My Suggestions

[Sports Fiend]

How about adding user-moddable situations to the game? These situations could be stored in independent text files and give the user a yes/no question. Each situation will have a benefit or a bad outcome, or possibly both. Situations can occur randomly.

For example, you could have the following situation:

[TV AD]
Description=Your agent calls and asks you if you will do a T.V. commercial for Viagra. The pay for the day will be $10,000. Do you accept Y/N?
Graphic=Commercial.gif
[YES]
Fame+1
Duration=365 (days)

or

[STEROID USE]
Description=A buddy of yours pulls you aside and tells you about a new steroid that is practically indetectable. Do you want to take it?
Graphic=Pills.gif
[YES]
Strength+2
Duration=30 (days)
[NO]
Morale+1
Duration=30 (days)
[RANDOM-YES]
Chance=30 (percent)
Outcome=SUSPENTION
Duration=30 (days)
Description=You were caught by the league during a random drug test for steroid use and suspended.

Just an idea.

How about building relationships between team players, like in The Sims?