Newcastle United boss Alan Pardew admits injury concerns for Cheick Tiote.
"Cheick has a calf strain so we will have to monitor him. We are sweating on him for next Saturday," said Pardew.
"Colo also has a knock but I'm not sure how that is. He is due to travel to Argentina but we will have to assess him, too.'
The news on Tiote is a major blow, given Pardew feels he has returned for pre-season in superb form.
"Cheick looks ten times better than he did last year, and I absolutely mean that," Pardew added.
"He did not come back well last summer, if I am honest. However, he has summered well this time and is in great physical shape.
"It is going to be a big season for Cheick. All my, what I would call big players, are important if we are to progress as a team, and Cheick fails into that category. He is in a good place."