Chelsea were beaten 3-1 at Arsenal on Boxing Day, their third defeat in four Premier League matches which sees them slip to eighth in the table.
Lampard had already complained about Chelsea's schedule by arguing it would be "almost impossible" to play the same team across two matches in 48 hours but hinted at dropping several star names after a lacklustre display at Emirates Stadium.
Liverpool boss Jurgen Klopp was among several leading figures who said Chelsea were genuine challengers this season but Lampard once again bristled at the suggestion they should be considered among the favourites, despite spending more than £220 million this summer on players.
"There will be some changes [against Aston Villa] and I knew that anyway," Lampard said. "I'm certainly not going to bang the drum about our quick turnaround after our performance [against Arsenal]. It is not the important point. Playing two games in two days, we have to make changes anyway.
"Some of them will now happen because of how the game went and people will have to come in and inject the energy and personality that is in our normal performances.
"Normally, the reason we went so many games unbeaten was because of that. We've come off that and we must come back on that quickly. Some of it is maybe where we're at as a squad.
"People wanted to talk us up as title contenders but I never accepted that was the case because we are not there. That takes time to build. Games like Saturday are ones we have to learn a very big lesson from, everybody myself included because when I see that in the first half today, I don't like it. That can't happen.
"We've seen some crazy results this season and a lot of teams have had ups and downs. At the minute we are in a position where out of the last four games, we've lost three of them and won one. That needs a reaction."