Paul Bin, William James Herve and Brayan Padilla were sidelined for much of 2019.
Lester will be posthumously inducted into the Montgomery County Sports Hall of Fame on Oct. 18.
The Terps gave up a Big Ten-leading 3.2 sacks per game last year.
Carter is tied for the sixth-most rushing touchdowns in program history.
“They are one of the strengths of our team."
The Terps continue to ramp up their workouts ahead of the Oct. 24 season opener.
Athletic director Damon Evans will take a 10 percent cut from his supplemental pay.
All three former Terps in the MLB helped their teams to the playoffs.