The Southampton fullback only had good words to say for his former Stamford Bridge teammate.
England and Southampton left-back Ryan Bertrand has paid credit to the man in possession of the number three jersey for the national team for so long, citing Roma man Ashley Cole an invaluable mentor in an interview with the FA website.
The former England fullback is regarded as a legend at Chelsea, having helped the club to a Premier League title, a Champions League win and a Europa League trophy.
Cole is not so well thought of at the Emirates, despite coming through as player for both his country and at club level while at Arsenal.
For a long time the 34-year-old could have been argued to have blocked Bertrand's route to the first team at Stamford Bridge, but it's hard for the Southampton fullback to have anything but respect and admiration for a player that would have undoubtedly been the ideal role model for a fellow left back.
"I learned a lot from him," he told the FA website in relation to Cole. "On the pitch and off the pitch, the way he went about his business was fantastic.
"We had a really good relationship on and off the field.
"As footballers, to learn off someone who has achieved so much in the game and has such a calm yet positive persona that Koeman does, it can only improve any player," added the 25-year-old.
"The tips he gives here and there are invaluable and we are managing to put them into practice.”