Sol Campbell has urged former club Arsenal to "do their utmost" to keep star forward Alexis Sanchez out of Chelsea's reach at the end of the campaign.
The Gunners failed to agree terms on a new contract with the Chile international earlier this season and have now delayed further talks until the summer.
Sanchez has grown visibly frustrated at the Emirates Stadium this term and recently hinted that he would be open to a switch to rivals Chelsea, but Campbell has questioned the player's desire by suggesting that money may have a say in any potential move.
"The club should do their utmost to keep Sanchez," he told Omnisport. "Signing players who are at his level will help with that and will also inspire players to believe they can go on and achieve great things next season.
"If you do [move to Chelsea], why are you doing it? Are you moving for football reasons or for the money? You have to ask yourself whether you fit in at that club. Sanchez is alone in his energy at Arsenal, but seeing other players at his level will help to push him and the club on."
Sanchez, who has 22 goals in 39 appearances for Arsenal this season, is also reportedly on the radar of German giants Bayern Munich.