With football running in his blood, Kroos was fed into the Hansa Rostock youth system at the age of twelve by his father, switching from hometown club Greifswalder SV close to the Polish border. It was not long before one of FC Bayern's network of scouts had spotted him and he headed south initially on an amateur contract, penning professional terms in January 2008. By that juncture, Ottmar Hitzfeld had already made him the then youngest-ever Bayern debutant, giving him a run-out at the age of 17 years and 265 days in a 5-0 win over Energie Cottbus on 26 September 2007.
So much, so young
Given the fierce competition for places in the Bayern team, Kroos was loaned out to Bayer Leverkusen in January 2009 and he went on to blossom into a key figure in the side which, under Jupp Heynckes, finished runners-up to Borussia Dortmund in the Bundesliga in 2010/11.
Despite Leverkusen's efforts to keep hold of him, Bayern were delighted to welcome him back at the end of his loan spell, heralding his return as if he were a major new signing. He had after all broken into the Germany set-up and become the youngest member of the squad which finished third at the 2010 FIFA World Cup, featuring in all his country's matches at UEFA EURO 2012 two years later.
He was a regular starter in the side for much of the 2012/13 season, until an adductor injury suffered in a UEFA Champions League tie against Juventus in April 2013 ended his season early. He therefore had to watch from the sidelines as Bayern enjoyed their most triumphant season ever, becoming the first German club to win the treble, but was back to his best the season after, playing a crucial part in the Bavarian's Bundesliga and DFB Cup wins.
After lifting the 2014 FIFA World Cup with Germany, Kroos transferred to Spanish side Real Madrid CF.