Derby County striker Nathan Tyson has been ruled out for the next month due to a groin injury.
The summer signing from Nottingham Forest was hurt during a pre-season friendly success against Aston Villa.
Tyson missed Saturday's 2-1 win over Birmingham City and must now wait until mid-September for his Derby debut, according to manager Nigel Clough.
"People said it must have been a big boost beating Aston Villa but we'd have swapped the win to have Nathan available," said Clough.
"He has had a scan and we think he is going to be out until after the international break in September.
"He will probably miss the first six games of the season - and we will miss him.
"He has had a couple of groin problems in pre-season but it is unrelated to those. A tackle made on him jarred him a bit. He tried to carry on and it got worse. It's just bad luck."