I'm not going to give up on Nadal yet, we all know he's getting kind of old and injuries affect tennis players a lot since it's a one player game, but he's not the type of player to give up easily, he had his downs throughout his career and bounced back, I'm expecting him to win a couple of big tournaments before he retires, if his body doesn't bring him down, the mentality to win will always be there with El Matador.
The major tournament that Nadal is still likely to win is the French Open, the only type surface that allows him to win lots of GS titles. This year's French Open will be held in May-June so Nadal has time to be able to recover from his injury even though the time that is still quite long is not a guarantee he will recover because it will really depend on the injury he experienced during the last Australian Open if it's too bad he might miss this tournament
Regarding Nadal's injury
I quote statements from his social media that Nadal's injury is not too serious
It was a level 2 injury to the psoas iliacus muscle in the left leg. Nadal also said he would rest for a while for his recovery which is estimated to take 6 to 8 weeks.
That means Nadal will recover before the 2023 French Open next May.
OK, clearly the French Open is his main target, this is his tournament having won it
ONLY 14 times previously.
This will be massive, both Nadal and Djokovic now have 22 GS titles, if Djokovic wins
it I cant see Nadal catching up. There is a bigger chance Djokovic could take Wimbledon
too to put a wider gap between them.