Paul Scholes has questioned whether Chelsea's centre backs Kurt Zouma and Fikayo Tomori are good enough.
The Blues lost 2-1 to Manchester City on Saturday in what was their third defeat to a 'Big Six' rival this season.
The former Manchester United star does not understand why Lampard's side are losing these big games.
'They keep going to these big clubs, playing really well and not winning games,' Scholes told the Premier League.
'That will be frustrating for him I think, because he knows he's got quality in his team but he's missing something.
'He's definitely missing something. He went to Manchester United, everyone said Chelsea were the best team, played really well, got beat 4-0.'
Scholes did identify Chelsea's central defenders as a cause for concern.
'I'd be a little bit worried about his two centre-halves, the way he wants to play are they good enough on the ball?' Scholes added.
'I think defensively they're okay but they look a bit nervous on the ball to me, which can create nerves throughout the team.'