The Chelsea boss admits that youngsters such as Tammy Abraham and Manchester United striker Mason Greenwood need to stay grounded before making an impact for their country.
Lampard said: "It's not just Tammy. It's a general rule. We get very excited with young talent and rightly so.
"We've seen it this season and that's why I've tried to stay pretty grounded when I get asked a lot about the youth, particularly earlier in the season, because I felt it coming.
"It's really hard to come into the Premier League, at the level it's at, and sustain performances or be in the side all the time."
The former England midfielder added that many players in his own team have experienced the ups and downs of playing at the highest level.
The 42-year-old coach said: "There's competition, games are hard. Whether it's Tammy, whether it's Mason (Mount), whether it's Fikayo (Tomori), whether it's Reece (James).
"They've all had periods of real input and playing regularly and periods where it's maybe not quite so much, in their own different ways.
"That's something we all have to be a bit calm with from the outside and expect that.
"The main thing from working behind the scenes is that they understand that and that they will have those little moments and not lose confidence.
"I'm always there to support them on that. But also they need to continue the work. That's the message for all young players, not just mine."