MADRID: Atletico Madrid striker Fernando Torres tweeted from hospital that he was OK after collapsing and losing consciousness from a clash of heads in a Spanish league game on Thursday.

"Thank you all for your concern and your messages of support," Torres wrote on Twitter. "It was just a scare. I hope to be back very soon."

Initial tests showed no signs of any serious spine or head injuries, but the former Spain forward will remain hospitalised as a precaution, Atletico said.

"He is stable and conscious," the club tweeted. "He'll spend the night in hospital and undergo more tests tomorrow (Friday)."

Torres collapsed hard to the ground after being hit from behind in a ball dispute late in Atletico's 1-1 draw at Deportivo La Coruna.

Players from both teams immediately rushed to Torres and desperately called for medical help.

One player tried to open Torres' mouth, apparently trying to clear his airways.

He was assisted for several minutes by doctors before being taken out on a stretcher and transferred to a hospital.

"(He) had to be rushed in an ambulance after being stabilised according to the usual protocol," Atletico said on its website.

Players from both teams and fans at Riazor Stadium watched with apprehension as doctors worked on Torres, some putting their hands to their heads and others covering their faces.

"Everybody was speechless in the dressing room because of what happened," said forward Antoine Griezmann, who scored Atletico's equaliser.

Torres was hit by the head of Deportivo midfielder Alex Bergantinos. The 85th-minute incident happened just outside the penalty area on Atletico's own field.

He'd only been on the field for 20 minutes, substituting Kevin Gameiro.

"It wasn't a good movement," Atletico coach Diego Simeone said. "But situations like this unfortunately can happen in the game. We hope the best for Torres."

The 32-year-old Torres, a former Liverpool and Chelsea player, won two European Championships and one World Cup with Spain.