Boa Morte also believes Campbell can still have a big future with the Gunners.
"He is exactly the type of player they needed and exactly the type of player that Sporting was looking for. He has all the qualities to play for them, and since he does a good job, I am sure that we will also benefit because he will come back even better.
"This is the most important thing," said Boa Morte, now a scout with Arsenal.
"He is truly powerful when attacking from the right. He is clearly a problem for defences."