Scotland will give Finn Russell and Darcy Graham all the possibilities of demonstrating his physical condition in time to face England on Saturday.
It is likely that none of the players appeared on Twickenham after a head of heads during the defeat of the six nations against Ireland on February 9, they stayed with brain shock.
Graham, in particular, seemed bad while he was stretched from the field before being taken to the hospital for more tests. Despite approving his HIA (head injury assessment), Russell was replaced by 'delayed symptoms'.
The World Rugby Broad Shock Protocols recommend a minimum suspension period of 12 days before returning to the game, although that program can also be adapted to each player depending on their history of brain shock and symptoms.
The assistant coach of Scotland, Pete Horne, has revealed that both players have been involved in light training with the rest of the team at the Oliva Nova training base in southern Spain.
Chief coach Gregor Towsend will now delay the name of his team to evaluate how the duo progresses.
Finn Russell was replaced due to delayed symptoms after a head of heads in the loss of Ireland
Darcy Graham was stretched from the field before being taken to the hospital for more tests
Graham is given every opportunity to demonstrate his physical condition before Scotland's visit to Twickenham
But Horne is still optimistic that both could be involved in some capacity, which would be a massive impulse for the Scots, since they seek to win the Calcututa Cup for the fifth consecutive time.
He said: 'Both are progressing well through the protocols that are in place. A 12 -day change is the best scenario. Both are going through their protocols at this time.
'There are still a couple of days until we finish the team. I think, depending on how the next few days, there is the possibility that both can play.
'They are not in full training, but we did some light skills and both were involved in that, which was good.
'Last week, they were working with the Fisios and the doctor, going through the early stages of it. And yesterday they joined for a little skills and things. We will see how they are outside the back of that.
'The view will be that they will do some training again and then see how we go from there. But both are progressing quite well.
'They are in a good mood and have certainly been part of the sessions so far.
'They still have certain things they need to mark. There will be no risks or anything taken. So I'm sure doctors are just above. Both are in hunting.
Horne said that the perspective of having Russell and Graham involved in some capacity has given the team an elevator while seeking to recover from the disappointment of the defeat of Ireland.
The former Back of Scotland added: 'The quality of these players is obviously simple for everyone to see, but there are also two great characters in the team. It is brilliant to have them here.
'Everyone was a little worried about Darcy, but I think that much of that was just caution, making sure that nothing could have gone wrong.
“It's what you would like to see, everyone takes it very seriously and err as caution.”
Towsend has made some adjustments to his squad, calling Scrum Half Ali Price, Center Cam Redopath and the extreme Ross McCann. The Matt Currie center retired after collecting a brain shock for Edinburgh on Friday night, while NO 8 Alexander Masibaka has allowed him to return to his club in France.
George Horne has also undergone a scan after suffering a facial injury in Glasgow Warriors' victory over Dragons on Sunday.
The performance of Scotland against Ireland has generated strong criticism, with an English expert over the weekend labeling the package like 'Weed Forwards'.
That comment was collected by Horne, who said he would only add more fuel to the desire for Scotland to do so five victories in the rebound.
“There has been a lot in the press about them to impose their physicality on our weed strikers, if you wish,” he added. 'So, I think we will have to make sure we are ready to match that.
'(That comment) is not something we have really talked about as a complete group. I read a couple of reports that made me laugh.
'Today I have been touching that to the boys, just to finish them. There is always some spices in a game of the Calcuta Cup and I am sure it will not be different this year.
'That is the kind of thing, certainly, if I were a player, that would bother me.
He would be anxious to go to the park and show that everyone was wrong.
“There will be some needle to add to what is always a very big game with the rivalry that is there.”