Let's see... has the player done any of these in a careless or reckless manner, or with excessive force:
• charges
• jumps at
• kicks or attempts to kick
• pushes
• strikes or attempts to strike (including head-butt)
• tackles or challenges
• trips or attempts to trip
...No.
Has the player committed any of these:
• a handball offence (except for the goalkeeper within their penalty area)
• holds an opponent
• impedes an opponent with contact
• bites or spits at someone
• throws an object at the ball, an opponent or a match official, or makes contact with the ball with a held object
...No, still good.
Has the player committed any of these:
• plays in a dangerous manner
• impedes the progress of an opponent without any contact being made
• is guilty of dissent, using offensive, insulting or abusive language and/or gestures or other verbal offences
• prevents the goalkeeper from releasing the ball from the hands or kicks or attempts to kick the ball when the goalkeeper is in the process of releasing it
• commits any other offence, not mentioned in the Laws, for which play is stopped to caution or send off a player
Hmm... he hasn't prevented the GK from releasing it, nor has he attempted to kick the ball while the GK is releasing it. If he's close enough for the GK to potentially kick him on the follow-through, then that would sound like playing in a dangerous manner. However, as the OP states that it's the ball that has hit the player, I read that as meaning he's far enough away that that's not part of the equation. GK should learn to be more aware of his surroundings.