Mark Pszonak contributed to this report.

The transfer portal never stops grinding. On Tuesday, former four-star running back Stephen Carr entered the portal, ending a USC career that lasted four seasons.

Recruiting: Carr committed to USC during the spring after his sophomore season. Despite taking official visits to UCLA and Arizona State in January, plus getting a late push from Oregon, he stuck with the Trojans on National Signing Day.

At USC: Carr made an immediate impact as a true freshman with 551 total yards and three touchdowns. In total, he rushed for 1,319 yards and 12 touchdown, while grabbing 57 receptions for 421 yards and one touchdown during his Trojans' career.

Potential landing spots: Being a grad transfer, several schools looking for some immediate help in their backfield for the 2021 season have already reached out. This group includes Indiana, Louisville, Pittsburgh, Arizona, Baylor and Rice.

Farrell’s take: Carr never broke out at USC as expected and we loved his ability in space and as a receiver but he couldn't get untracked while the other elite backs in his class did. This is a good chance for a refresh at a smaller program and Pitt seems to be the most aggressive and active so far. His impact is a bit questionable however based on his up and down production so far.

Impact Meter: 6.5 out of 10

IMPACT METER

The Transfer Portal continues to change the way college football programs recruit and manage their rosters so we here at Rivals.com continue to evolve our coverage. Each time a player of note enters the portal, we will examine their potential impact on the college football landscape and assign an impact rating, both when they enter the portal and when they choose a destination. The scale is from 1-10 and the description below explains the scoring scale.

1.1-4.0 — Not a big impact expected, likely a non-starter and down the bench depth player.

4.1- 6.0 — A solid impact can be expected in the right scenario and has the potential to battle for a starting job.

6.1-9.0. — A high impact player who won’t change a program but will certainly be a very good contributor and starter.

9.1- 9.9 — A very high impact player who should start the moment he steps on the field and will change the outlook of a program immediately.

10 — A franchise transfer who has a chance to be an All American and one of the elite players in college football.