Kylian Mbappe came off with an apparent injury as Monaco came from behind on two occasions to open their Ligue 1 title defence with a thrilling 3-2 victory against Toulouse on Friday night.
Zinedine Machach netted for the visitors after just six minutes at the Stade Louis II Stadium before Jemerson levelled for the champions with a header after 28 minutes.
Andy Delort stunned the hosts once more after he put Toulouse back in front with 53 minutes gone only for Radamel Falcao to head Monaco back on level terms shortly before the hour mark.
Kamil Glik nodded home Joao Moutinho's free kick from close range with 20 minutes remaining to complete Monaco's comeback and kick-start their campaign with three points.
Monaco's thrilling five-goal victory however, was tainted after an injury sustained by Mbappe in the second half.
Mbappe, the 18-year-old linked with a move to Real Madrid and Barcelona, left the field after 74 minutes with an apparent knee injury and was replaced by Allan Saint-Maximin.
He was attended to on the pitch by the medical staff, and after walking off under his own power, continued to be be treated on the sideline.
"It's nothing serious. I think in two or three days, it will be better," Monaco coach Leonardo Jardim said after the match.
Mbappe scored 26 goals in 44 appearances for Monaco last season and was handed the No.10 shirt by Monaco for the forthcoming season.
Paris Saint-Germain, whom Monaco beat to the Ligue 1 title last season, will begin their campaign -- with world-record signing Neymar set to feature -- at home to newly promoted Amiens on Saturday.