Jarryd Hayne looks set to play the St Louis Rams in the San Francisco 49ers' season finale.
The 49ers' top running back Shaun Draughn succumbed to a knee injury on Wednesday, significantly boosting Hayne's chances of playing.
Coach Jim Tomsula said Hayne has made significant progress in learning how to be an NFL running back, but conceded he still lacks some of the instincts that come with experience.
"He continues to work his tail off and get better," Tomsula told reporters.
The coach gave little away on whether Hayne would play against the Rams on Sunday (Monday AEDT).
News that makes sense
Your trusted source for staying up-to-date with the world around you. Get free daily news updates and analysis, straight to your inbox.
While Draughn is out after being placed on the injured reserve list, another running back recovering from injury, Mike Davis, could potentially push Hayne out.
Tomsula said he is keen to play Davis, who will practice this week with the first team after two months out with a broken hand.
"I'd like him to be," Tomsula, asked if he would like to use Davis, said.
"But, we'll find out exactly where we are at."
The 49ers usually take three running backs into games and have Hayne, Kendall Gaskins, DuJuan Harris and possibly Davis to choose from.
Tomsula said Hayne showed with some of his runs and pass protection plays in the loss against the Detroit Lions on Sunday how much he has improved in feeling and seeing the game.
"He knows the assignments," Tomsula said.
"Would I tell you that it is absolutely natural to him yet? No.
"But he knows the assignments."
Tomsula said Hayne, who has immersed himself in the 49ers' playbook since arriving at the NFL team's Santa Clara headquarters in April, knows what he needs to do at walk-throughs at practice and in team meetings.
It is in a game situation where Hayne still sometimes lacks the instinctual moves that other running backs who played the game since childhood have.
The coach used the example of situations where two linebackers line up against Hayne and quarterback Blaine Gabbert.
Hayne needs to know in a game situation who to target.
"If you put him on a board and put him in a walk through, he knows it," Tomsula said.
