Lampard, who is on Chelsea's tour to America, believes Chelsea will benefit from the increased competition for places.
"We proved to be a great team and a great unit in the second half of last season," he told the club's official website chelseafc.com.
"This year maybe we are slightly different because we have more new young players coming in.
"There might not be the settled togetherness that we had on the pitch as that side because we had been together a long time.
"But there is an excitement about our team as well and that's probably the main difference.
"Everyone is trying to impress, and you never lose that in pre-season, there's not one manager I've met yet who will close the door on any player.
"We have to perform at a high level to stay in the team because of the quality of the squad we have."
English Premier League
French defender Gael Clichy has signed a new four-year deal at Manchester City.