At 39 years old, turning 40 on September 9th, he should have opened the door to a return to his playing career. With his experience, he should have been on the sidelines as a coach. However, the player refuses to grow old and retire. Typically, some players, as they approach retirement, choose to move to a less competitive league, or even the Arab League to earn more money before retirement. However, that doesn't seem to be the case for Luca Modric. He's almost 40, but he's still playing in Europe's top leagues.
I'm not sure why Luca Modric is still playing in Europe's top leagues. But it will certainly be an extraordinary experience, as even at his advanced age, he's still capable of competing with younger players. The presence of Luca Modric will at least be a short-term solution for AC Milan's midfield, and hopefully this will produce the desired results, where AC Milan can regain the Scudetto, while for the next step, AC Milan still has to bring in young players who are quite promising for the future of the team.
surely the choice was also dictated by the fact that he can't stop and in fact he will give his advice to the younger ones who can make an impact technically and physically on the pitch, because he will certainly be good but he can't keep up with the pace of the younger ones.