Scotland are counting the cost of their 26-13 win over Japan in the first Test of their summer tour.
Alasdair Dickinson has dropped out of consideration for Saturday's second, and final, match - with Gordon Reid already on his way out to join him.
Glasgow Warriors' Reid will join the squad in Tokyo on Monday, with fellow prop Dickinson heading home for further care and assessment on an injury. The Edinburgh player damaged a hamstring in the third minute of Saturday's victory at the Toyota City Stadium.
In addition, the fitness of four other Scotland players is giving cause for concern, though there do not appear to be any immediate plans to replace them.
John Barclay (shoulder), Willem Nel (knee), Duncan Taylor (hamstring) and Ryan Wilson (knee) all require further treatment and might be forced to miss the match at Tokyo's Ajinomoto Stadium. None are being replaced at the moment.
In the case of Taylor, Barclay and Wilson, there is already enough cover within the squad and although losing Nel would be a major blow, the Edinburgh man is confident he will be able to play some part in the game.
Nel said: "I should be okay for next week. They came out all guns blazing and they are a physical team so it took us a while to break them down.
"It was a fairly close game. We need to get quicker to the breakdown and not give away silly penalties."
The match in Toyota City provided Nel with his second Test try - which came early in the second half against 13 men and allowed his side to relax and control the match.
He continued: "I don't go into games looking to score a try but if it happens, it happens.
"It is good to get over the line. They have run us close. We need to go back to the drawing board, especially at the breakdown.
"We were in their 22 four or five times then gave penalties away. We need to tighten up and see us through."
Nel, South African-born and qualified on residency, is one of only four props in the squad so if he does not recover in time, Scotland could be in trouble with not enough props for a complete set on the replacements bench.