I think I speak for essentially everyone here when I say, "fk this guy's boss". Old mate here in this thread slacks off or 2 days, his boss is already very respectfully thinking of firing him.
It's not 1920. The modern middle manager has more invested in his fantasy football league than his direct reports -- and by some magnitude. Grow up.
Are you serious? If anything, the boss should be happy someone is improving their skills on their spare time instead of learning everything on the job.