Georgia Tech fired defensive coordinator Al Groh, the school announced on Monday.
Coach Paul Johnson is expected to name an interim coordinator during his afternoon press conference. The most likely candidates are defensive assistants Charles Kelly and Andy McCollum, according to ESPN.com.
The Yellow Jackets' defense has struggled, allowing more than 600 yards in two of the past three losses and an average of 46 points per game during that span.
"The Institute has decided to go in a different direction, which I respect," Groh said in a prepared statement. "I appreciate all the help and input from (assistant defensive coaches) Charles Kelly, Joe Speed and Andy McCollum, and the effort of all the players.
"I aimed to give the best that I had every day. It's been an honor to be a part of the legacy of Georgia Tech football. I feel positive that this is a good time in life to move on to a new situation."