Scott Brown was non-committal over the prospect of facing England after leading Scotland to a 1-0 victory over Slovenia.
The Celtic midfielder had the captain's armband again after Darren Fletcher dropped to the bench for the World cup qualifier at Hampden.
The 31-year-old missed the first three games of the campaign after announcing his international retirement in August, but came back to help out his former Parkhead boss, Gordon Strachan, after his form and fitness improved dramatically in the early part of the season.
But the timing of the next game against England on June 10 complicates matters as Celtic begin their Champions League campaign on July 11-12.
Brown told Sky Sports: "We'll see how it goes. It's going to be a hard situation because we are going to be back so early in June.
"Last year I had the six weeks off, so I need to look after my body as well and see how it is for Celtic.
"I need to maintain the level and fitness that I have been playing at all season. If I can maintain that as long as I possibly can, you never know."
Brown was never likely to declare himself available in the immediate aftermath of the win, without discussing the situation with Celtic boss Brendan Rodgers, who had six of his players in the Scotland starting line-up on Sunday.
Defeat or even a draw was likely to spell the end of Brown's international career given Strachan was set to quit if qualifying hopes were effectively ended.
The midfielder benefited from an extended summer break before Rodgers came in after finishing last season early amid hamstring problems.