The Pole will attempt a title defense in Doha this week
The Spaniard's path to the final includes several notable clay-courters
The American has won 34 tiebreaks than Roger Federer.
Stefanos Tsitsipas is top seed and Andrey Rublev is seeded second for the ABN AMRO Open.
"There are only a few days to go before a decision is made and what remains for us to do is hope for a positive outcome," Novak Djokovic's brother told Serbian agency Tanjug.
The 2021 US Open champion joins fellow Flushing Meadows champions Iga Swiatek, Bianca Andreescu and Sloane Stephens in field.
The 2022 US Open champion is back in good health and ready to play.