Speaking to BT Sport, Lampard said that the arrival of Cesc Fabregas from Barcelona played a part in his departure.
The pair clashed many times when Fabregas was with Arsenal and in the Champions League with Barca, and Lampard believes their inability to be friends lead to the club parting ways with the former England midfielder.
"[Fabregas and I] never played together! They let me go to get Cesc in," said Lampard.
"Me and Cesc never really got on well on the pitch so they didn't think we could share a dressing room."