The former central midfielder is to replace outgoing Gladbach boss Marco Rose, who has agreed to join Borussia Dortmund at the end of the current campaign.
A former central midfielder, Alonso spent the final three years of his playing career in Germany with Bayern Munich, accumulating 117 first-team appearances between 2014 and 2017, helping the club to win three successive Bundesliga titles.
The former central midfielder secured his requisite coaching badges in 2018 and was subsequently appointed as coach of Real Madrid’s Under-14 team, before moving to take up the position at La Real’s B team last summer.
The report from Germany claims Gladbach are confident of appointing Alonso but he has yet to give confirmation from his own environment, having had a contract renewal offer on the table from the Basque club.
Alonso has spent two years back in San Sebastian while Gladbach have suffered a slump in form this season having qualified for the last 16 of the Champions League.