Harlequins director of rugby Conor O’Shea has revealed Mike Brown’s recovery time from the symptoms of concussion could be as long as a piece of string.

The 28-year-old has been suffering headaches since returning from Six Nations duty and will sit out this weekend’s trip to Sale Sharks, having been stood down from all rugby and club activity until the final game of the season at the earliest.

O’Shea is in contact with England head coach Stuart Lancaster over Brown’s likely fitness for this year’s World Cup.

And he is confident resting his man will increase the full back’s chances of starring for his country for years to come.

“Mike is desperate to play, but we have to protect him from himself,” he said.

“We’re not certain when he will be back.”

“We are all concerned for him. He has had the right scans and they revealed there is nothing long-term untoward.

“But he is still suffering headaches and we have to wait until he is right.

“If we look after him he will be fit to play the 2019 World Cup as well as this year.”

O’Shea confirmed the arrival of Highlanders centre Winston Stanley this week and revealed the club’s recruitment plans for next season are nearing completion, although one or two deals remain to be done.

“We are pretty comfortable with where we are and if the season started tomorrow, we’d be happy with what we have,” he added.

“There are a couple more signings to be confirmed between now and the end of the season.”

Back row Natani Talei is in talks over extending his Stoop stay beyond the end of the season, and O’Shea has admitted the ball is in Wales centre Jamie Roberts’ court over his future.

He said: “According to Wales media he [Jamie Roberts] is heading back there.

“We’ll wait and see what his decision is.”