ATHENS, Ga. -- Georgia's football team is less than a week into spring practice and the Bulldogs' widely watched running back competition has already changed course.

Rising senior tailback Carlton Thomas' decision to transfer took last season's second-leading rusher out of the mix and could create further opportunity for other performers -- possibly Keith Marshall, whose dynamic skill set in high school indicates that he can do many of the things Georgia might have asked of Thomas.

The Bulldogs figure to have five tailbacks compete for playing time in the fall -- six if you count former walk-on Brandon Harton, who rushed for 101 yards against Kentucky and 98 against New Mexico State last season.

Here's a look at the five players who will rank among the top contenders for playing time in the backfield:

Player: Isaiah Crowell

Class: Rising sophomore

Last year: Rushed for 850 yards in 12 games and won SEC Freshman of the Year honors despite missing time with injury and discipline-related issues

Strengths: Probably Georgia’s best every-down back because of ability to run between the tackles plus good enough speed to get around the edge. Also capable of catching passes out of the backfield although he had only 59 receiving yards as a freshman.

Weaknesses: Questions still remain about whether Crowell is tough enough to fulfill his star potential. He dealt with a series of injuries last year before finally suffering a high ankle sprain against Kentucky that cost him much of the remainder of the season.

Comments: Crowell and his coaches and teammates say he is better prepared for this season and is working to be more accountable, but the proof will be in the pudding. He was not a reliable teammate last year and spent much of the second half of the season nursing injuries as Georgia’s running game crumbled without him in the backfield.

Player: Ken Malcome

Class: Rising redshirt sophomore

Last year: Appeared in six games, including two starts, and rushed for 174 yards on 42 carries.

Strengths: Can be one of Georgia’s tougher runners, as evidenced by the physical plays he made late in last year’s SEC championship game against LSU.

Weaknesses: Malcome did not display a particularly positive attitude for much of last season -- he briefly quit the team early on, publicly complained about his treatment by the coaching staff and was suspended for a game along with Crowell and Carlton Thomas -- but Coach Mark Richt recently complimented him for turning a corner with improved attitude and effort.

Comments: Early last fall it looked like Malcome might never play a significant role at Georgia, but these appear to be sunnier days for the rising sophomore. He was buried on the depth chart for much of the 2011 season, but seems to have his head in the right place and could enjoy a much more active role in the offense this season.

Player: Richard Samuel

Class: Rising senior

Last year: Played in eight games, starting four, and rushed for 240 yards on 82 carries.

Strengths: At 6-foot-2 and 243 pounds, Samuel looks the part of a hard-nosed running back more than any other player on the roster. He certainly isn’t afraid to put his head down and crash head-first into an opposing defender, either.

Weaknesses: Samuel has been unlucky throughout his career in that he can’t seem to stay healthy for long stretches of time. Certainly that has been a factor in his struggling to make a major impact at either running back or linebacker, where he spent the 2010 season as a redshirt. He also has struggled to become an elusive runner capable of gaining regular yards after contact.

Comments: The tragedy in the ankle injury Samuel suffered on the final play of the Bulldogs’ win against Florida last year was that he played perhaps the best game of his career that day against the Gators. He scored the game-winning touchdown after making several smashmouth runs on the drive, but the injury forced him to miss the next five games and he failed to gain a yard in the bowl loss against Michigan State. That has been the story of Samuel’s career. He seems to be the forgotten man in this tailback race, but will factor into the equation somehow.

Player: Keith Marshall

Class: Freshman (enrolled in January)

Last year: Rushed for 1,891 yards and 25 touchdowns as a senior at Millbrook (N.C.) High School before graduating early and enrolling at Georgia in January

Strengths: The five-star freshman is a speed demon, which will make him an instant home-run threat for the Bulldogs. Coaches and teammates have credited Marshall for his level of preparation entering spring -- which fits his billing as a studious, high-character athlete.

Weaknesses: Marshall (who is listed at 5-foot-11 and 190 pounds) is one of the smaller players on the field at all times. Observers will naturally wonder whether he can take the pounding an SEC tailback receives until he proves that his size will not limit his effectiveness.

Comments: Georgia fans are excited about Marshall's potential for good reason. He wasn't named the nation's No. 5 overall prospect by ESPNU for nothing. He will be an exciting addition to the offense and by all accounts a good citizen away from the field. Expect to see him make an impact right away.

Player: Todd Gurley

Class: Freshman (not yet enrolled)

Last year: Rushed for 2,600 yards and 38 touchdowns in leading Tarboro (N.C.) High School to a state championship.

Strengths: Known for his athleticism -- he contributed at both safety and running back in high school -- and tough running ability, Gurley looks like a potential every-down back on film. He is not the breakaway runner that Marshall is, but he might be more capable of running both between the tackles and around the edge.

Weaknesses: Gurley will start behind the 8-ball somewhat in this running back race simply because he is not on campus for spring practice like Marshall is and will join a group of players who have already played in SEC games when he finally arrives this summer.

Comments: If Gurley performs well when the Bulldogs open preseason practice, it would not be a huge surprise to see him carve out some playing time right away. He has the skills to help the team early, but might need time to pick up the offense so he can truly compete with the more established backs on the depth chart.