George North has been stood down by Northampton Saints and the Wales wing will consult an independent specialist after he was seemingly knocked out during the defeat at Leicester Tigers.
North appeared to be unconscious after he was caught in mid-air by Adam Thompstone when taking a high ball at Welford Road last Saturday.
The British and Irish Lions flyer, who suffered a series of concussions last year, was permitted to return to the field following a Head Injury Assessment, a decision which Saints have been criticised for.
Saints on Tuesday revealed that North will not be considered for selection for the time being and the Premiership club defended the way its medical staff dealt with the situation.
A club statement said: "As at every Aviva Premiership match, the Saints' medical team has access to video footage to be used to assist the pitchside assessment of injuries. It is important to note this video footage is not always the full range of replay angles available to the TV viewing audience at home.
"The medical team can only base their decisions on the evidence available to them at the time of assessment. World Rugby protocol dictated, given the evidence available to the medical team, the use of a Head Injury Assessment.
"George was fully assessed by the doctor away from the pitch using the established protocols and processes, and passed fit to return to play.
"As with all such injuries, if evidence suggesting a loss of consciousness had been available to the medical team at the time of assessment, George would not have been allowed to return to the field of play.
"All rugby supporters will no doubt be delighted to learn that George remains well. Nevertheless, Northampton Saints continues to place player welfare as its number one priority, and is referring George to an independent expert as part of the club's ongoing assessment process and George will be stood down from play until this process is complete.
"There is a concussion management and monitoring protocol in place for all Aviva Premiership matches which provides for independent review and the opportunity for more detailed investigation.
"This is an ongoing process with several stages, and the club looks forward to contributing to this.
"Additionally Northampton Saints is seeking to work with all parties to improve the availability of all footage that may assist team medics with injury management."