Chelsea captain Cesar Azpilicueta watched training as he recovers from the head injury he suffered against Southampton.
The Chelsea defender was concussed after being kicked in the head by Saints star Sekou Mara as he attempted an overhead kick on Saturday.
Azpilicueta appeared to have been knocked out as he lay on the ground motionless.
He quickly received medical treatment which included being given oxygen.
After a few minutes of assistance he was taken off the pitch before being taken to hospital.
Chelsea released a statement on his condition revealing he was well enough to watch his team-mates train.
The club said: "The club's medical team are closely monitoring Cesar's condition, adhering to the important concussion protocols in place to ensure his safety.
"Cesar observed training today, before he starts working towards returning to the pitch."