He will obviously lose his number 1 ranking since he reached the quarterfinals in the 2022 tournament depnding on the performances of Ruud, Tsitsipas ad Djokovic in the Aussie Open.
It is unlikely that Nadal will play as well. So going into the Aussie Open Ruud may be the number 1 seeded player - with Tsispas at 2, Djokovic 3 and Medvedev at 4.