If there was a perfect time for Arsenal to get Rodrigo I would say it is now, since the arrival of Mbappe it was said that it will be Rodrigo who will be most likely sold off, last season his form and injury didn’t help him because he was injured all through out and didn’t get good minutes. Now that he is alive he is not looking like someone that Alonso values that much. The presence of even this young lad, Gonzalo is another big obstacle for him, so I think he will be open to leaving for game time.
Arsenal already have one of the best defensive players in the world and the new midfield look isn’t bad but the attack is poor, Rodrigo is one of my favorite players and seriously he is packed with talent, his addition to arsenal team with Gyokeres will be massive threat to the other clubs if they pull this off
With the inconsistency in starting game, if Arsenal can offer Real Madrid what they are demanding, the can get Rodrigo without a doubt but which player are they going to sell to get that amount of money to buy him. Since the beginning of the World club cup, Xabi hasn't start him but there is a rumor that he want him to be part of the squad. He will be happy to go to Arsenal if he is going to have a full game instead of the regular back stage Xabi is doing.
If Rodrigo should join Arsenal, it's going to be a very good combo and another advantage for them is they can switch him on both places and still perform better. If the striker guy Viktor they are aspiring to get comes to the club perhaps get an injury, Rodrigo can be a better alternative but until they brings him first. The challenge I think they will have is where Real Madrid will be asking from Arsenal and who Arsenal is going to sell to get all these players on their squad.