In a statement on their official website, the club said:
"Following the tests carried out on our player, Toni Kroos, by the Real Madrid medical department, he has been diagnosed with a pubalgia. His recovery will be monitored."
The former Bayern Munich has been diagnosed with a pubalgia - or sports hernia.
It is believed that Kroos will be out of action for a minimum of six weeks and is expected to be back in mid-September at the very earliest.
Reports are that the German midfielder's recovery time could be twice as long as that but will undergo a surgery if the problem ploughs on.
Real Madrid have been silent in this year's summer transfer and having been struck by the injury of Kroos could somewhat see the Los Blancos finding his replacement.
However, summer arrival David Alaba can also function as a midfielder, a decision Carlo Ancelotti might go in for.
Toni Kroos retired from international football after Germany's exit from Euro 2020, making 106 caps for Die Mannschaft.
On the back of twenty-eight appearances in the LaLiga for Madrid last season, Kroos managed to score 3 goals with ten assists.
Kroos since joing Real Madrid has won a number of major trophies including three Champions League titles.
Real Madrid signed Kroos from German Bundesliga club Bayern Munich for a fee believed to be in the region of €30 million as he signed a six-year deal with the White Angels.
Real Madrid will begin the 2021-22 LaLiga campaign away with Alaves on August 14.
