Despite injury problems, midfielders Mount and Barkley were on Thursday named in Gareth Southgate’s England squad for Euro 2020 qualifiers against Montenegro and Kosovo.
Mount limped out of Tuesday’s 4-4 Champions League draw with Ajax due to an ankle injury, while Barkley has a similar issue and not featured since October 19.
Ahead of Saturday’s early kick-off with Palace at Stamford Bridge, Lampard said: “Ross has got an ongoing issue so he’s not in the squad tomorrow. It’s a conversation that I will have with Gareth (Southgate) or Steve (Holland) with Ross to see how it pans out for him over the next 10 days.
“With Mason, he’s in the squad. We’re giving him another 24 hours and we’ll make a call on that one in the morning.”