Georgia Tech has played from strength at B-back this season, as freshman Dedrick Mills and sophomore Marcus Marshall made a stout 1-2 combination at the featured running back position in the Yellow Jackets’ spread-option offense.

Mills brought head-on power, while Marshall contributed speed and an open-field menace. The depth was particularly useful when Mills missed four games because of suspensions and a concussion and Marshall missed one with an upper-body injury. The pairing is no more, however, as Marshall announced Wednesday that he will transfer in January.

From his Twitter account, Marshall thanked teammates, coaches and the Tech community for their support and for the opportunity to play for the Jackets the past two seasons.

“At this point, I have decided to move on from the GT football team and will be transferring in January to continue my football and academic career,” Marshall wrote.

Marshall was not the only Tech player to declare his intention to leave Wednesday. Redshirt freshman Dorian Walker, who played a special-teams role this season, also announced on Twitter that he will transfer after the semester. Neither will play in Tech’s bowl game.

Last season, Marshall became the first freshman to lead the Jackets in rushing yards since Joe Burns in 1998, finishing with 654 yards. Starting three games, his playing time increased as the season went along. However, Mills’ arrival last January as an early-enrollee from Ware County High cranked up the competition at the spot. Coach Paul Johnson declared the two “1A and 1B” during preseason and awarded the starting job in the season opener to Mills, making him the first freshman to start a Tech season opener since 2008.

Coaches’ confidence in Mills and his ability to gain tough yards was demonstrated in his 11 rushing touchdowns (nine of which were runs of seven yards or shorter) and his average of 15.2 carries per game. It was the most for a B-back since Anthony Allen (18.5) in 2010.

Coaches sought to give Marshall the ball on the perimeter, often running double options to the sideline with him and quarterback Justin Thomas. Marshall’s home-run ability was evident in his five plays from scrimmage of 50 yards or more this season, tied for eighth in the country. He was perhaps at his best in two games at the end of the regular season, against Virginia Tech and Virginia, when Mills was sitting out with a two-game suspension for violating team rules. Playing with a physical style while still flashing his speed, Marshall rushed 35 times for 270 yards and two touchdowns in the two games.

“He hung in there and was tough,” Johnson said after the Virginia Tech game.

In an interview with the AJC in mid-November, Marcus's father Warren Marshall said his son had had second thoughts about his future at Tech, as might any young player going through adversity. However, both father and son said that he was happy and enjoying school. Coach Paul Johnson said that Marshall responded in a positive way toward losing the starting job to Mills.

“It was motivating,” Marcus Marshall said. “I felt like everyone wants to be a starter, so that was disappointing. My mindset was to get better for every game and try to prove I could be the starter and help the team any way I could.”

In a text message Wednesday, Warren Marshall called it a “very difficult decision for Marcus and the family as a whole.” He likewise expressed his thanks to Johnson and the coaching staff for the opportunity.

“We do not wish to be a distraction to GT and their bowl preparation, so this will be our only statement at this time,” Warren Marshall wrote in the text.

The younger brother of former Georgia running back Keith Marshall, Marcus Marshall has three seasons in which to play his final two of eligibility. He could go to another FBS institution, sit out, and play his final two seasons. At an FCS school, he could play immediately. As a senior from Raleigh, N.C., he chose Tech over Vanderbilt, Wake Forest and James Madison.

Going into the offseason, Mills likely will be backed up by Quaide Weimerskirch and KirVonte Benson, redshirt freshmen who have played special teams this season. Mills has been suspended twice and will need to walk the straight and narrow for his final three seasons. Tech has a commitment from one likely B-back prospect, Jerry Howard from Northwestern High in Rock Hill, S.C., and may pursue another.

Walker played in all 12 games this season and was credited with three tackles, one interception and one pass defensed. In a Twitter message, Walker expressed thanks and appreciation for the opportunity and support he has received the past two years.

“After a long and prayerful consideration, I have decided to move on from Georgia Tech,” he wrote.