Blues coach Pat Lam said his centre remembers little from the 59-12 loss in Christchurch and was unlikely to play again this season.
Stanley's head injury is the latest in a series - he suffered a bad concussion while playing for Auckland in last year's ITM Cup.
"It's a concern - another concussion - he's had a few now,'' said Lam today, adding Stanley would go through normal concussion testing with Blues medical staff.
Asked if he would be ruled out for the rest of the season, Lam said: "A good chance. It's not definite but we've just got to prepare that that is the case.''
When queried whether the medical protocols were sufficient for concussion injuries in rugby given the recent examples of NFL players becoming depressed after suffering head knocks during their careers, Lam said: "Concussion is part of contact sport. You don't want it happen but chances are high when you're smashing into each other.''
Stanley's injury was by far the worst on the Blues' list. Prop Tony Woodcock's arm injury which forced him from the field in Christchurch is unlikely to prevent him from playing the Highlanders at Eden Park on Saturday night.
Lam said he could get outside fullback Rudi Wulf back from a shoulder injury and loose forward Chris Lowrey could return from concussion suffered three weeks ago against the Hurricanes.
If the Blues reached a nadir with their loss to the Crusaders, it's not going to get any easier against the Highlanders, who battled their way to a deserved 16-11 victory over the Bulls in Dunedin on Saturday.
Lam said his players were down and the challenge for him and his coaching staff would be to get them up again.
"There is that mental barrier. Obviously everyone is hugely disappointed and it's a matter of selecting the right team to bring that energy and enthusiasm and those guys who can step up.
"Without a doubt the Crusaders were clinical, well stocked and a good side. They really took it to us. When you have a team like that if you make errors they will punish you. Certainly once the momentum got going it was difficult to stop. The boys kept trying but it was a difficult night for us.''
Lam is missing six players to the All Blacks at their training camp in Auckland this week, although two, hooker Keven Mealamu and prop Charlie Faumuina, are injured. Ali Williams, Piri Weepu, Ma'a Nonu and Woodcock will return to the Blues on Wednesday.
Lam insisted the four wouldn't be too distracted by their All Blacks duties ahead of the first test against Ireland on June 9.
"They're professional,'' he said.
