Chelsea playmaker Oscar has been released from hospital after being assessed for a head injury, sustained during Sunday's draw with Arsenal.
The playmaker collided with Gunners keeper David Ospina in the 16th minute and was substituted at the interval.
Jose Mourinho said his staff were a "little scared" but says the Brazilian slept at home and would be at training.
"We saw his face swelling and at half-time we didn't want to go for any risks," said Mourinho, 52.
New rules mean the club doctor has the final say on whether a player with a head injury should play on.
The Premier League introduced the regulation at the start of the season, as well as bringing in a tunnel doctor who acts as an extra pair of eyes to assess the severity of incidents on television monitors.
Replays appeared to show Oscar, 23, exhibiting the fencing response - involuntary arm movements that are an indicator of concussion - as he lay on the Emirates turf.
However, after a touchline conversation with Chelsea's medical staff - including first team doctor Eva Carneiro - he returned to the pitch.
Last season Tottenham were criticised for letting goalkeeper Hugo Lloris play on in the goalless draw against Everton after being knocked out in a collision with Romelu Lukaku in the 78th minute.
Brain injury charity Headway said Spurs were guilty of an "irresponsible and cavalier attitude".
Guidelines from the National Institute for Health and Care Excellence state people should not play any contact sport for at least three weeks after suffering concussion.