SALE Sharks boss Steve Diamond felt it was “strange” Worcester Warriors prop Nick Schonert was allowed back onto the field despite passing a head injury assessment.

Schonert lay face down on the turf following a collision with James Phillips in the first half of Warriors’ 21-15 defeat at Sale on Sunday.

The 26-year-old was treated by medics before heading down the tunnel to receive the required head injury checks.

Diamond did not expect Schonert to return but the South African-born front rower re-emerged 10 minutes later after being given the all-clear to play.

According to World Rugby’s law, any clear or suspected signs of symptoms of concussion must result in “immediate and permanent player removal”.

Diamond said: “We have got to take the medical people’s (advice) there.

“They are obviously switched on and know what they are doing.

“But it did look as if he had a bad knock.

“We trust (Warriors’) people know what they are doing.

“Safety is the key but I thought it was strange that he came back on.

“If he passed the protocol then fair do's.”

Warriors director of rugby Alan Solomons said he did not see the incident but backed the club’s medical department to make the right call.

“He went off for a HIA,” Solomons said.

“We have got excellent doctors and I leave it to them.

“At that stage I didn’t observe him.

“I didn’t stay and watch him. The medics were tending to him.

“There were other issues that I was concerned with.

“I knew he was in good hands with the medics so I am not going to pass any comment.”