We travel to Keegan's latest club Manchester City on Monday, a club that the former England manager inspired to an automatic promotion following his arrival at the end of the 2000-01 season.
City had just suffered relegation from the Premiership and Keegan was tempted by the opportunity to galvanise the blue half of Manchester. He has certainly delivered.
Comparisons have been made with the effect he had on Newcastle United, a club he took over in a similar position back in 1992. The rest, as they say, is history, but Les - who played a major role in the Newcastle side from 1995-97 - has only fond memories of his time with Keegan.
"He bought me to Newcastle and I don't think I'd be wrong in saying he was one of the better managers I've worked for in my time," reflected the striker who scored 50 goals for the Magpies.
"He knew how to get his players motivated. Some people have called him a quitter in the past when he's left certain things, but I've got nothing but good things to say about him.
"When I played under him I thought he was a very good manager and enjoyed my time with him."
Keegan's style of management has always been described as motivational and Les said the players often felt ten feet tall when they emerged from the changing room before a game.
"You did and that was the sort of effect he had on his players. They were all up for playing for him and he used to carry a good buzz about him.
"It was a roller coaster with more highs than lows to be honest with you. We went through that season, it's old hat now, but we should have won the title - it was an amazing time."
The season in question was 1995-96, where Newcastle surrendered a 12-point lead on Manchester United to lose the title, but Les insists there was more to Keegan's reign on the Tyne than that particular memory.
"There was, even before I got there he had Newcastle playing the sort of football that everybody enjoyed watching. I used to meet people from London and they would say 'I hope you lot win the championship' and would rush home to watch them on the telly because they were so entertaining.
"That's what he did. What you knew with a Kevin Keegan team was that there would be goals - in either net.
"His philosophy was they might score two, but we'll score three or four. It was all out out attack - probably not good for our defenders, but great for the rest of us."
Les Ferdinand is better qualified than most to explain the excitement and expectation Kevin Keegan brings to a football club and has 'nothing but good things to say about him'.