Rudiger, 32, joined Madrid on a free transfer from Chelsea in 2022. Over three seasons he featured in about 157 matches and helped the club win eight trophies. But this campaign has been more difficult.
According to German outlet BILD, Rudiger's contract will not be renewed. Alonso has doubts over his consistency and injury record, the report adds, pointing to a thigh problem picked up in early September that is expected to keep him out until November.
In Rudiger's absence, Eder Militao and Dean Huijsen have become Madrid's preferred centre-back pairing and have drawn praise for their performances. Meanwhile, Rudiger is believed to be one of the club's highest earners, making his role as backup less tenable under the current regime.
The possibility of his exit gains further weight given past tension. Earlier this year, Rudiger was reportedly involved in a heated training ground bust-up with teammate Jude Bellingham. According to reports in El Chiringuito, Rudiger delivered a harsh tackle in a small-sided drill, Bellingham responded with an insult, and teammates had to step in to separate them. The matter was later smoothed over behind closed doors.
Rudiger's career has spanned several clubs: Stuttgart in Germany, London clubs Chelsea, Roma in Italy, and now Madrid. He has also earned around 81 caps for Germany.
At present, Real Madrid sit top of La Liga, having won seven of their first eight matches. They recently opened their Champions League campaign with a 2-1 win over Marseille.
Madrid will next travel to Getafe in La Liga, before hosting Juventus in Europe.
If Rudiger does depart next summer, Madrid face a decision: whether to invest in new centre-backs or promote further from within.
FC Barcelona have reportedly reached an agreement with Borussia Dortmund to sign Karim Adeyemi, with the Germany international now closing in on a move to the Spanish champions.
Chelsea are reportedly willing to listen to offers for Alejandro Garnacho just 12 months after signing the Argentine winger from Manchester United.
Jurgen Klopp has revealed the extraordinary lengths Liverpool went to in their failed attempt to sign Kylian Mbappe from Monaco in 2017, describing the pursuit as the club's "most expensive non-transfer."
Crystal Palace have completed the signing of Spain international defender Oscar Mingueza on a free transfer from Celta Vigo, with the move subject to international clearance.
