Frank Lampard has lamented the "typical modern-day reaction" that accompanied Andreas Christensen's knee injury.

Denmark defender Christensen was expected back in training on Saturday but will not be ready to face Morecambe in Sunday's FA Cup clash.

The 24-year-old took a heavy bang to the knee in a clash with Jack Grealish in Chelsea's 1-1 Premier League draw with Aston Villa on December 28.

Christensen was left in a heap on the ground as Villa pressed on and capitalised to level through Anwar El Ghazi.

In response to questions about Villa playing on with Christensen injured on the field, assistant coach and ex-Chelsea skipper John Terry posted on social media: "He should have got up."

Now Blues boss Lampard has confirmed Christensen's injury as a direct result of that clash with Grealish, revealing his frustrations with criticism of his defender.

"I'll set the record straight on that one – Andreas' injury was absolutely from that moment in the Villa game," said Lampard.

"It's probably a typical modern-day reaction where Andreas has taken stick. He's out but the injury isn't too bad which is good news for him. He'll back in training with us on Saturday."

Chelsea will host League Two side Morecambe in Sunday's third-round FA Cup clash, bidding to hit back to winning ways after the chastening 3-1 loss to an inspired Manchester City last weekend.

Lampard will make a host of changes to take on Derek Adams' Shrimps, with the Blues having had a clutch of academy stars training with the first team this week.

Spain goalkeeper Kepa Arrizabalaga could be primed for a rare start if Lampard opts to rest in-form summer signing Edouard Mendy.

Kepa looks set for an extended stint behind Mendy in Chelsea's pecking order whatever happens on Sunday, and Lampard has refused to rule out letting the 26-year-old leave Stamford Bridge in the January transfer window.

Asked whether he sees Kepa's future as a Chelsea player, Lampard replied: "Well at the moment he's our player and I think the situation is clear, Edou (Mendy) has come in and he's been playing regularly as the number one for us.

"And when Kepa has come in he did well, and he's trained really well. His attitude around the place has been brilliant.

"So I won't be drawn on that one at the moment, he's our player and we'll see how January goes, but I don't want to be alluding to what might or might not be."