Northampton Saints have confirmed that winger George North will be on the sidelines until the end of April following further tests on a head injury.
The Wales international was knocked unconscious following a collision with Nathan Hughes during the Saints' 52-30 win over Wasps last Friday.
This is not the first time that North has suffered head injuries - the 22-year-old was knocked out twice during a Six Nations clash against England in February.
Medics have advised North to spend a month away from playing, and the club plan to keep track of the winger's progress during this period before he is re-assessed at the end of April.
"We have listened to the advice we sought and George will be taking some time away from the field," director of rugby Jim Mallinder told the club's official website.
"Throughout this process it is important that George's welfare comes first and that he is treated patiently and calmly, only returning to action when all of the medical team are happy for him to do so."
Hughes was banned for three weeks for recklessly kneeing North in the incident.