Michigan State was fortunate to have a pair of four-year starters in the secondary as the Spartans won 42 games in the past four seasons.
"It's not changing that much," Drummond said. "We were all a close unit and we were all vocal and we all push each other.
"It's just like two of my brothers leaving, but we've still got great guys in Trae Waynes, R.J. Williamson and guys who have played football and understand the game."
Williamson stepped in for Lewis – who was out with a knee injury – early in the 2013 season and also played the majority of MSU's win at Northwestern following Lewis' ejection for targeting.
He likely will take over for Lewis at the strong safety spot, just how Waynes stepped in to start at corner last season.
The rising junior said he senses the need to step up and focus on leading with Dennard gone.
"We have a lot of leaders in that group," he said. "We've got Kurtis and we've got R.J. So I know it's solely not on me but I know I do have to step it up as a player and a leader."
Even as the faces change, the "No Fly Zone" expects it will hold strong next season.
"We've got all the confidence in the world for the guys that step in," Drummond said. "It's basically just pushing each other like we did this past season and just step up everybody's game."
The defense as a whole, which loses six starters from the No. 2-ranked unit in the nation, carries the same expectation.
"You guys will see," Drummond said. "We are a very deep unit. The coaches do a great job recruiting guys and guys do a great job of catching on and learning. You guys will see.
"We definitely got some playmakers and we are definitely excited for the guys stepping in."