Paul Dummett could be a doubt for Newcastle United's opening Premier League fixture of the season against West Ham United.
The Geordie defender was missing for the Magpies' 2-0 win over Burton Albion at Pirelli Stadium.
Steve Bruce could not guarantee he would be ready for the mid-August clash with the Hammers.
Bruce said: "Dummy, unfortunately, nicked a calf last week at Doncaster.
"That's a little bit of a concern. We'll see how that is.
"We don't think it's anything untoward.
"We think he'll be touch and go for the start of the season, unfortunately."
That means that Kell Watts could come into contention for the Premier League clash for a bench role with Jamaal Lascelles, Ciaran Clark and Federico Fernandez strong candidates to start.
But there was better news for United on Callum Wilson who was taken out of the squad for Burton as a precaution.
Wilson could even take part in next Saturday's home friendly with Norwich City at St James' Park.
Bruce said: "We expect him to be OK.
"It's more a precaution.
"So we expect him to be (back in the) middle of the week, something like that.
"We hope that he can be ready for Norwich."