Juan Martin del Potro could feature in Saturday's doubles at the Davis Cup final providing he recovers from his opening match against Ivo Karlovic.
The 2009 US Open champion earned a point for Argentina as they finished the opening day at 1-1 with Croatia in Zagreb, Del Potro needing four sets to see off Karlovic.
With a crucial doubles rubber coming up on Saturday before the final two singles matches on Sunday, the 28-year-old could turn out again for his country - if selected by captain Daniel Orsanic.
Leonardo Mayer and Guido Pella had been named as Argentina's doubles pair, but Del Potro hinted that could change depending on his fitness.
"I don't know," he said when asked whether he will play on Saturday.
"If I feel good tomorrow the captain will decide between the four players."
His recovery may not come in time after a tough second half of 2016 for Del Potro, having made his comeback after spending much of the last two years out with wrist injuries.
He was able to secure the first point for Argentina in Zagreb, though, something he was delighted to do.
"I think Ivo played very good tennis in those moments and of course I was nervous after I lost the second set but in the end I had to take the longer road to victory," he added.
"It was a really difficult match for me, but I never gave up. I got frustrated when I could not break his service, but I did well in the third and fourth sets and I think that was the key of the match."