Many expect the 43-year-old to take over as coach for Real Madrid. However, it has not been confirmed.
On Sunday, Bayer Leverkusen, who appear to finish second in the league champions Bayern Munich, will face Borussia Dortmund in Alonso's last home game.
Last season, Alonso led Bayer Leverkusen to the club's historic first Bundesliga title. They also won the German Cup and set a notable European record for the number of consecutive competitive matches without defeat, 51. In the Bundesliga, Leverkusen remained unbeaten in all 34 rounds, which no German team had previously achieved.
The former defensive midfielder played for Real Madrid between 2009 and 2014.
