Modric has already answered a hundred times about moving to Al-Nasr, he says that he really hopes to stay in Real Madrid, but the contract has not yet been signed. Perhaps there is nothing wrong with this, if a player feels that he is in good shape and can continue to play at a high level, then why should he not continue to play for his team. In any case, if his performance deteriorates, Ancelotti can always replace him.
There is also the problem that with age the likelihood of injury increases, remember how many injuries Ibrahimovic had when he continued to play in recent years. But Modric always seemed to be doing well, I don’t remember him spending much time with any kind of injury.
I heard that Real Madrid demand Modric to not play for Croatia if he want to stay in Real Madrid for the next season, which may his biggest reason to think carefully before make a decision.
Yeah, in the recent years, Modric never suffered any serious injury, it's mostly below 10 days. What make it interesting, the older Modric is, the injury time become shorter, unlike other matured players. Check
https://www.transfermarkt.com/luka-modric/verletzungen/spieler/27992Modric was almost bringing Croatia to gets the trophies several times and i am sure he won't be missed the opportunities to play with Croatia again for Euro 2024 moreover if we see from his current age i think this is his last chances to playing with Croatia national team before he got retired so i think Modric will give him priority to playing with Croatia and about his future in Real Madrid it has been discuss before unlike Toni Kroos who successfully to extended his contract with Real Madrid but Modric future is still uncertain in this team because although his contract will be ended at the end of this season but Real Madrid still haven't thinking to give him contract extension even Ancelotti personally to says no further talks for a new contract with Modric yet
Modric was lost to compete with young players such as Jude Bellingham, Federico Valverde, Aurelien Tchouameni, and Eduardo Camavinga because Ancelotti are more prefer to played these players than him it proven from his records this season that Modric was playing 24 total with Real Madrid but he was starting the match from the bench 12 times and if he want to gets more minutes to play Modric have to thinking look for new clubs and he can considering the offers from Saudi Arabian clubs or MLS