It would be nice to have the capability of being able to generate players on the fly, at least before the season starts. Sometimes I just need an average player that doesn't exist within my league outside of team rosters.

You can delete players in Roster Management correct?

no you can cut players from roster management, that moves them to free agents.

If you want to add a new player, I think there is an option somewhere. Its easier of though to just find some random useless free agent and edit him (and add him to a team if thats what you want)