Karlos Williams is a touchdown-scoring machine. Charles Trainor Jr. Getty Images

The Buffalo Bills have a pretty good running back in LeSean McCoy, but his backup is having a great rookie season himself.

Karlos Williams, the Bills' fifth-round pick, has missed time due to a concussion, but he returned to action on Sunday against the Miami Dolphins. Entering the game, Williams had scored a touchdown in each of his first four career games, but he took that statistic a step further this week.

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In the first half of Sunday's game, Williams scored on an 11-yard touchdown run, his fifth touchdown in as many games. With that, he became just the fourth player in NFL history to score a touchdown in each of his first five career games.

Had Williams not suffered a concussion earlier in the season, he could have played a huge role with LeSean McCoy dealing with injuries of his own. If he stays healthy, Williams should be a big part of Buffalo's offense down the stretch.