Carlos Hyde has been slowed by a foot injury over the past week. Cary Edmondson USA TODAY Sports

The San Francisco 49ers are looking at other backfield options with their top two running backs dealing with injuries.

The 49ers brought in former New Orleans Saints running back Pierre Thomas for a workout Monday, according to a report by ESPN. Thomas spent eight seasons with the Saints, rushing for 3,745 yards and 28 touchdowns while catching 327 passes for 12 more scores.

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Starting running back Carlos Hyde labored through the second half of Sunday's 25-20 win over the Baltimore Ravens while battling a foot issue that caused him to collapse to the ground without being touched at one point.

Hyde vowed to play in Thursday's game against the Seattle Seahawks, saying he did not make the foot any worse in Sunday's contest. San Francisco coach Jim Tomsula referred to the injury as similar to a bruise.

Backup Reggie Bush missed Sunday's game due to a calf strain but Tomsula said he is "very optimistic" that Bush will be available Thursday. Bush has already missed three games and had just four carries for seven yards.

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