Injured Fofana out of Six Nations
The 29-year-old, who has 44 caps for France, suffered the injury late in the first half just after scoring one of his team's seven tries.
"He has a rupture of his left Achilles tendon," the club said in a statement.
"He is out of the Six Nations."
French Top 14 leaders Clermont added that Fofana will be unavailable for a "long period" with a decision on surgery to be taken on Sunday.
Fofana grimaced with pain when he suffered the injury just as he offloaded the ball to full-back Nick Abendanon to score one of his team's tries.
France start their Six Nations campaign on February 4 against England at Twickenham.
Fofana's absence is a huge blow to Les Bleus — four years ago he scored a majestic try from 80 metres at Twickenham.
He was expected to partner teammate Remi Lamerat in midfield but is now likely to be replaced by either Gael Fickou (24 caps) or Yann David (four caps).
Agence France-Presse
