Chelsea transfers adviser Piet de Visser has urged the club to re-sign Nathan Ake from Bournemouth.
Netherlands international Ake switched from Stamford Bridge to the South Coast for £20m in 2017, having struggled to break from the academy into the Blues first team.
Ahead of Chelsea's trip to Ajax in the Champions League, De Visser told De Volkskrant: "Ake should have played for Chelsea by now. He's so good.
"How often does he not score with his head? He has timing and insight. I hope they buy him back.
"That boy is perfect for them and he has played with Lampard."