Didier Drogba believes Chelsea lost the world's best defender when they allowed William Gallas to join Arsenal.
Gallas made the switch across London as part of the deal that took Ashley Cole in the opposite direction on transfer deadline day.
The parting of the ways has been anything but smooth, with Chelsea launching an outspoken attack on the France defender days after the move.
But Drogba is in no doubt over the quality of his former team-mate, who is regarded as one of the most versatile defenders.
'William Gallas' departure is a massive loss,' Drogba said in the Daily Express. 'He is one of the greatest defenders in the world.
'When it comes to the ability to play anywhere, he is the best on the planet. It is very hard to part with a player of Gallas' quality.
'But if that is what the club have done, it must be because they see sense in the deal.'
Drogba also revealed he himself was the subject of a summer move by French champions Lyon, who failed to lure him away from Stamford Bridge.
'It would have been very interesting to join Lyon,' he said. 'But the reality is I have two years left on my Chelsea and I like to honour my contracts.'
Lyon were eager to bring the former Marseille striker back to France, with president Jean-Michel Aulas the architect behind the attempted swoop.
'I feel flattered by Mr Aulas' interest as Lyon are becoming an increasingly respected European club. They frighten their opponents,' added Drogba.
'I often get phone calls from Bernard Lacombe, the president's adviser.
'He asks me how things are going here and whether I would be interested in returning to France one day.
'But Chelsea have proved how much they value me.
'I have become an essential player for them, and I feel genuine respect coming from them.'