The Dutch coach told the young centre-back that his development was best served at St Mary’s - but the player still went ahead and completed his big-money move to north London.
Chambers featured regularly for Arsenal during the first half of the season, but has often been overlooked by Wenger since the turn of the New Year.
Koeman warned Chambers against Arsenal move
Koeman was quoted by BBC Sport as saying: “I said to Chambers: 'Really, I don't think it's a good moment to change and to go to Arsenal because I think you need to develop yourself much more,'
"Normally, you will play here much more than you will play at Arsenal, but finally it's always the decision of the player."
Chambers dropped in recent weeks
Because of various injury problems, Chambers played in all but one of Arsenal’s opening 15 Premier League fixtures. The one match he missed, against Hull City in October, was because of suspension after accumulating five yellow cards.
The former Southampton starlet, who is capable of playing at centre-back or full-back, played the full 90 minutes against Crystal Palace on Saturday - but was left out of the Gunners’ previous five league fixtures.
Wenger admits he has used Chambers too often
This lengthy spell on the subs’ bench came after Arsenal boss Arsene Wenger admitted he had played the youngster too much during the first half of the campaign.
“For a 19-year-old player, he has played too many games,” Wenger was quoted as saying by the Guardian in December. “They all hit the wall after 15, 17 games. You have to give them a breather, refresh and get them back again. At the moment, to have that responsibility in every single game is a lot on a player of that age.”
Was Chambers right to ignore Koeman’s advice - or will he regret his decision to join Arsenal? Have your say in the comments below!