Ampadu, 18 is regarded as one of Chelsea’s most promising youngsters, and after making only five appearances last season, it was thought that new manager Lampard would want him to stay and work with him this term.
But Ampadu, who played more games for Wales last season than he did for Chelsea, did not travel to Japan with the rest of Lampard’s squad last night.
Both Aston Villa and Lampard’s old club Derby have been keen on the midfielder, who can also play in defence.
Lampard said: “Ethan is not here as we’re looking at the possibility of him going on loan for the season.
“I tried to sign Ethan on loan at Derby last year, so I’m a big fan, but with the minutes he played last year, I have to think of the bigger picture and the interests of Ethan and of Chelsea.
“The idea that he could play a lot of games somewhere is good for him and we haven’t brought him here while that is up in the air.”
Another Chelsea youngster, midfielder Mason Mount, signed a new five year deal on Monday.
“It’s a massively proud moment for myself and my family,” mount said.
“I joined this club at six years old and it was always my goal to play for the first team one day. Even though I went out on loan for two years, my goal was always to come back and play – my mind has never really moved from that.
“I’m really looking forward to the coming season now and working hard to have an impact here at Chelsea. I’ve been at the club for a long time already and hopefully I’ll stay for a long time to come.”
He added: “Young boys feel like there’s a pathway here and that they’re going to get a chance, which gives us confidence to train with the first team, try to get into the team and work hard to be involved.
“That’s my goal for this season – I want to fight for my position and having 80 games under my belt over the last two years has given me a really good platform coming back. It’s really exciting times at the moment.”