France forward Mamoutou Diarra is looking for a huge improvement on Saturday against the Czech Republic following Les Bleus' mauling by Slovenia.
The Tony Parker-less French suffered a 77-61 defeat, and now take on a Czech group which is flying high after demolishing Poland "Now we must beat the Czechs," said Diarra in L'Equipe.
The 2-metre tall Diarra scored eight points in just 12 minutes.
"We did not produce our best match in Slovenia, especially on defence where we failed to unsettle them," he said.
"We had instructions but we did not follow them. As far as the defence is concerned, there is still a lot of work to do.
"Now, considering what happened, we must beat the Czechs and bounce back all together. We have already experienced things, we lose and we win all together.
"We have the spirit to fight back, we are far from defeated."
Parker, the San Antonio Spurs point guard who captained France at last summer's Eurobasket in Sweden, chose not to make himself available for national team duty this summer.