Assuming the contact was only from the momentum of ball chasing and it was immediate, probably not. If it was not immediate, meaning it would not have occurred if the "defender" obtained the ball, then possibly a foul if not trifling. If it was careless, reckless, etc. then the referee must judge the effect and intent.
The "defender" could be cautioned based on the manner of the foul, if careless, dangerous, tactical, etc.