Wenger feels Campbell's presence within his own squad, both on and off the pitch, has proved some much-needed nous, even if it could not ultimately help his youthful side deliver a trophy.
"I believe it is fantastic to see how well Sol has come back. When he has his mind on the game he is unbelievable," said the Arsenal boss, who is in the process of discussing with Campbell options for a possible new contract.
"Sol is a strange guy because when he is focused sometimes he can be very detached - but when he is in with you, he is 100 per cent, not 99, that is what I like.
"In the dressing room as well he has been very good.
"If Sol sets himself a target he is an unbelievable soldier."
Wenger believes Campbell, a former England skipper, still has something to offer the national team, his last of 73 caps - including three World Cups - having come in the defeat to Croatia at Wembley which ended hopes of reaching the 2008 European Championships.
"I just see that many centre-backs are injured, so why not?" said the Arsenal boss.
"Sol has got the experience and it is up to Capello to decide."
Wenger continued: "Of course others have an advantage because they are younger, but if England have a problem in numbers Sol is always there.
"I do not select the team and I do not say Capello has to take him - I just say you compare him today in the Premier League with the other centre-backs and he does not suffer in the comparison."