Ziyech has been limited to just seven Premier League appearances since his summer move from Ajax due to a couple of injuries, the latest being a hamstring problem.
He last played in the victory over Leeds United on 5 December, but has now returned to training and is building towards match fitness.
Lampard is not convinced that he is ready to start this weekend, but it sounds like the Morocco international will at least be on the bench against Pep Guardiola’s side at Stamford Bridge.
‘He’s fit to train, he’s trained the last few days, two or three days so I have to make that decision as to whether he’s ready to start,’ Lampard told a pre-match press conference.
However, it is less good news for James, who sat out of the draw against Aston Villa last time out and remains sidelined this weekend.
The right-back is not expected to be out for long, with Lampard describing his injury as ‘small’.
‘Other than that, Reece James is out,’ said the Blues boss. ‘Reece has got a small hamstring problem.’
Lampard’s men have won just one of their last five Premier League matches, losing three of them to Everton, Wolves and Arsenal.
They have dropped to sixth in the table and will be overtaken by City if they suffer another defeat on Sunday.
Ziyech will be an important boost for Lampard, though, having looked very impressive in his handful of appearances for his new club so far.