Not really. You should only need a relatively limited vocab to communicate on a pitch and he should pick that up pretty fast.
Anyone that's played a summer kickabout with a group of multinational students in the Bournemouth environs knows you can pick up the main calls used in football in another language inside an hour or two of kicking it around.
Complex tactical instructions sent on by the manager may be a little trickier but you'd think anything being communicated would have been worked on at some point in training so even then he should be able to get the message with the help of a simple diagram on one of those notes.