Chelsea manager Jose Mourinho is sweating on the fitness of big-name summer recruit Michael Ballack.
Ballack went off after just 26 minutes at the Millennium Stadium
The German midfielder limped out of the Community Shield with a hip injury and may miss the start of the new season.
"He had a kick in the muscle and he couldn't run but I hope he will be back soon," Mourinho said after Chelsea's 2-1 defeat by Liverpool in Cardiff.
"We have quite a few players not in condition and we need players back, so I hope it's not a big deal."
Ballack, who came on a free transfer from Bayern Munich in May, will definitely miss his country's friendly against Sweden on Wednesday.
And he joins Joe Cole, Petr Cech, Claude Makelele and William Gallas as doubts for the start of Chelsea's Premiership defence against Manchester City next Sunday.
That quartet did not figure at the Millennium Stadium and Mourinho felt a lack of options among his substitutes played into Liverpool's hands.
"Today our bench was not very good, with some kids," he added.
"Liverpool could inject fresh blood at the same time as some of my players became really tired. They were broken.
"They were in better condition than us, you could see the difference between Frank Lampard and Sissoko."
But he is unconcerned by his team's form ahead of the new season.
Chelsea went behind to a ninth-minute goal from John Arne Riise, which Mourinho blamed on naivety after the Norwegian was allowed to run the length of the field.
And in the second half he felt his team were always running out of steam against fitter opponents.
"With that first goal you must make a fault, get a yellow card and get organised but this is the time to make mistakes," stated Mourinho.
"Liverpool had more intensity and pace, qualities that make a team better. They had that and we didn't.
"We had a big percentage of the ball possession, but Liverpool defended with intensity and looked dangerous when they counter-attacked.
"I keep saying they are a difficult team to beat and they can go to every game with an ambition to win.
"They are a good team but over 10 months of competition we will be there."