Jeremain Lens has been told he must work harder if he wants to regain his place in the Sunderland side.
Lens joined the Premier League strugglers from Dynamo Kiev in July, but has failed to make a significant impact, firstly under previous boss Dick Advocaat and now Sam Allardyce.
The Netherlands international has been dropped to the bench in recent weeks and Allardyce says he must up his work-rate if he wants to get another opportunity in the starting XI.
He told the Sunderland Echo: "I think what Jeremain has to do overall, like they all have to do, is to lift his level up in terms of work-rate.
"There is no doubt at this level of football the size of the work-rate needed.
"With each position, I have the levels of an elite performer and an average performer for a Premier League player. It's easy for me to monitor.
"It's not just Jeremain, but some of our players have been told that they haven't reached the average and I expect them to reach that average very quickly.
"In finding the right team, Jeremain has had the knock back.
"But he'll have an opportunity somewhere down the line that he's going to have to grab.
"I'm still not satisfied with the team and results, so somewhere he'll get picked and he'll have to be ready to take it.
"Hopefully then he stays in."
Sunderland visit Crystal Palace on Monday having won just one Premier League this season - a 3-0 defeat of local rivals Newcastle United.