While striker Cavani battles to be fit after sustaining a calf injury, Matuidi misses out for France at the Nizhny Novgorod Stadium on Friday because of suspension.
The two used to be team mates at Paris St Germain before the 31-year-old Frenchman moved to Juventus last year.
“I worked with Edinson for a very long time. We have not spoken recently, but I know him well enough to tell you that he is a very generous man, who does not give up on anything, and I know that he will do everything, right up until the last moment to be on the pitch,” Matuidi told a news conference on Wednesday.
“I do not know if they are bluffing (about the injury). That’s for the Uruguayans to worry about. But there are injuries that can be quickly healed and others for which there is no miracle cure.”
If Cavani does not recover, Matuidi believes Uruguay will be hampered.
“Uruguay without Cavani is not the same thing. You don’t easily replace one of the best attackers in the world. It would be a handicap for them," he said.
“But their way of playing and defending, won’t change too much I don’t reckon.”
Matuidi, whose caution in the last-16 win over Argentina ensured an automatic one-game suspension, reckons Uruguay will prove tough opponents.
“Not necessarily a nightmare, but a difficult match. They let in very few goals. But we are able to trouble any team, because we really have quality in attack. It's up to us to put ourselves in a position to bother them,” he added.
(Reporting by Mark Gleeson in Nizhny Novgorod; Editing by Ed Osmond)
