Neymar strained his right adductor muscle and had to come off seven minutes into Brazil's 1-0 win over Cameroon on Tuesday, while fellow forward Mbappe fell awkwardly before halftime in France's 1-0 victory over Uruguay and was also withdrawn.
The only blot on Brazil's sheet was a first half injury to forward Neymar who limped off the pitch as he will now be closely monitored by club doctors just eight days before his Paris Saint Germain side face Liverpool in a crucial Champions League game.
And Mbappe has a shoulder contusion after falling heavily in France's 1-0 win over Uruguay at the Stade de France.
It appears likely that both players will miss PSG's Ligue 1 match against Toulouse on Saturday, but their real target will be Wednesday's Champions League match against Liverpool at the Parc des Princes.
No end in sight for crypto sell-off as bitcoin breaches $4 500
But it seems likely that one factor is the ongoing turmoil of Bitcoin Cash, the third most valuable decentralized cryptocurrency. However, one thing which remains consistent is that Bitcoin continues to dominate over 50% dominance in the crypto market.
"He felt some discomfort in the groin region and left [the pitch] complaining about that discomfort", Rodrigo Lasmar told Sportv. "He will need a bit more time to evaluate it and take a scan, but in principle it is not a serious injury".
Liverpool now hold a one point lead over PSG heading into matchday five but the Ligue 1 giants would be banking on home advantage to put themselves back into one of the top two slots.
Neymar took to social media to confirm what the doctor had said.
Neymar was replaced at Stadium MK by Everton's Richarlison, who scored the only goal just before half-time.
We closed the year happy for the work done so far, these last games were important to recover from the biggest hit that was the World Cup, we remained strong, focused and aiming to be increasingly better.