This week in practice, Thomas had a crash course in learning San Francisco's pass protections and zone run-blocking system. According to Thomas, terminology is the biggest difference between the 49ers and the Saints playbooks.

"When I don't get something right, I put that pressure on myself to get better," Thomas said. "I'm coming into their family, and I want to make sure I fit in because when I get out there, I'm not going to mess up. I'm going to make this 49ers family proud for bringing me in."

With Pierre Garçon (foot) and Mike Davis (hand) ruled out, Thomas figures to play a significant role in San Francisco's game plan versus the Falcons, a team he has faced 16 times in his career. Kendall Gaskins and fellow newcomer Shaun Draughn are the other two active running backs.

Thomas is confident that his offsite training will allow him to hit the ground running in his 2015 debut. The adrenaline boost won't hurt either.