The San Francisco 49ers worked out five running backs on Monday, which head coach Kyle Shanahan utilized as a bonus day because of the longer week. The 49ers do not play a game until Monday night.

The only name Shanahan revealed was Jeremy McNichols.

"I can tell you, Jeremy McNichols we worked out because we had him here throughout training camp and stuff," Shanahan told reporters. "There were four others."

Now, thanks to Field Yates of ESPN, we know who those four other running backs were. Shane Vereen, Charcandrick West, Andre Ellington, and Matthew Dayes joined McNichols in the workout.

Dayes and McNichols have the least experience of the group. The 49ers announced on Tuesday that Dayes was among three players signed to the practice squad.

"We're trying to see how our guys are, how the health of Breida is," Shanahan said on Monday. "[The result of the MRI] was better news than anticipated, but it's still not great news. So, we'll see that over the next couple of days. It was good to take a look at some guys [on Monday]."

Ellington and Vereen have been in the league since 2013, and West since 2014. Ellington is the cousin of former 49ers wide receiver Bruce Ellington (2014-16), who is now with the Houston Texans.

Andre Ellington has spent time with the Arizona Cardinals (2013-17) and Houston Texans (2017). Vereen has played for the New England Patriots (2011-14) and New York Giants (2015-17). West spent his entire career with the Kansas City Chiefs (2014-17).

The Tampa Bay Buccaneers made McNichols a fifth-round draft pick out of Boise State in 2017 while the Cleveland Browns selected Dayes out of NC State two rounds later.