Lionel Messi was among a host of sport identities to show their support for Neymar after the Brazil forward was ruled out of the World Cup with injury.

Social media networks were flooded with messages of solidarity for the 22-year-old, who suffered a fractured vertebra in Brazil's 2-1 quarterfinal victory over Colombia on Friday.

"Get well soon my friend, Neymar Jr," Messi wrote on his Facebook page just hours before taking to the field for Argentina's quarterfinal clash with Belgium.

Germany midfielder Mesut Ozil bemoaned Neymar's absence from his team's semifinal against Brazil in Belo Horizonte on Tuesday.

"Neymar, I am unhappy. Get well soon," the Arsenal playmaker said.

Ozil's Germany and Gunners teammate Lukas Podolski also expressed dismay.

"Happy with our victory today, can't wait to face #Brasil, sad for @NeymarJr hope you get better soon," the striker said.

Italy striker Mario Balotelli, who has exchanged regular messages with Neymar on social media, said: "Neymar, my brother, I am with you. Be strong!"

Former England striker Gary Linekar alluded to the tourament's loss of one of its marquee names.

"Neymar is out of the World Cup with a broken vertebrae. What an absolute bummer!"

The news even transcended sporting codes with basketballer LeBron James tweeting: "Hate to hear the news on Neymar! What a player. Have a speedy recovery/Get well asap man! #HesABeast # MyKidsFavPlayer."