What's the problem? Players are allowed to push an opponent holding the ball.
7.1 Playing a match
A match is started by a kick-off.
After the kick-off, any player who is onside may take the ball and run with it.
Any player may throw it or kick it.
Any player may give the ball to another player.
Any player may tackle, hold or push an opponent holding the ball.
Any player may fall on the ball.
If you can push a player on the pitch - why can't you push him off the pitch?
How do they push somebody without using their arms then? Do then mean a shoulder-charge perhaps?