Swansea striker Bafetimbi Gomis collapsed six minutes into Wednesday's match at Tottenham and was carried off the field on a stretcher, though he was not hospitalised.
Gomis was returning to the centre circle after Nacer Chadli scored for Tottenham when he fell to the pitch on his hands and knees.
He was attended to for four minutes and left the field on a stretcher, by which point he was conscious and wearing an oxygen mask.
Good news emerged from Swansea at half-time that Gomis was fine and had not been hospitalised.
"He is fine," a Swansea spokesperson said. "He is in the medical room. It is something we have been aware of -- it is something called a vasovagal condition.
"We have always been aware of it and it has happened before. He has had all the medical and cardiology tests with us."
The 29-year-old has a history of fainting, with at least three such spells in 2009 when he was with Lyon in France.