Tennis icon John Isner favors Alcaraz over Sinner to win the Career Slam: "It's strange he hasn't done it already."

The Grand Slam race between Carlos Alcaraz and Jannik Sinner has once again ended in a 2-2 tie this year, just like last year. While Carlos has six and the Italian has four, neither of them has a Career Slam. Winning all four Grand Slam titles this year, at least once, is a remarkable feat that tennis icon and Nadal's arch-rival, John Isner , is certain the Spaniard will achieve before the Italian.

This is what the former American tennis player and great server said bluntly on the Nothing Major podcast that he shares with fellow former tennis players Sam Querrey, Jack Sock and Steve Johnson.

His main argument is the fact that Carlos only needs to win the Australian Open, the next one to be played: "I think, simply because it's the next Grand Slam... It's strange that he hasn't done so well in that tournament ," he also analyzed, in line with Querrey's opinions.

"Zverev has beaten him, Djokovic has beaten him in recent years, so he should be fine now. It's strange that he hasn't won it yet, at the level we saw him at the US Open. If he does, no one will beat him, as we know, " he added.

Sam Querrey also supported that idea and added another compelling argument: "It seems more likely that he will win on hard court than Jannik on clay [since the Italian only has Roland Garros left]. I don't think Jannik dominates on clay. He could have won this year, but it feels like, well, Jannik faces Musetti, and then Casper, and then Alcaraz; it's a bit more difficult," he concluded.

The Australian Open will be the first to be decided in February, then in June we'll know who wins Roland Garros. Carlos may have just one shot at fulfilling Isner's prediction.