Spurs had identified the 33-year-old as their preferred choice to take over from Jose Mourinho, who was sacked last week, just days before the League Cup final against Manchester City.
Criticisms of Mourinho had increased after a shocking collapse to Dinamo Zagreb in the Europa League and a series of poor results which saw them drop down the table.
However, the decision to sack Mourinho still came as a surprise, especially given the timing and Daniel Levy’s previous belief that he was the man to end the club’s trophy drought.
Former Tottenham midfielder Ryan Mason, whose playing career was cut short by a fractured skull sustained at Hull City, was placed in temporary charge for the remaining weeks of the season.
Mason led his boyhood club out at Wembley yesterday, but they were outclassed by Pep Guardiola’s Man City, who secured a 1-0 win thanks to Aymeric Laporte’s late header.
Spurs had set their sights on Nagelsmann as Mourinho’s long-term replacement but are now in danger of losing out to Bayern Munich.
The Bavarian giants dominated under Flick last season, winning the Bundesliga title, the German Cup and the Champions League.
Flick recently announced that he will be leaving his role at the end of the current campaign, forcing the Bayern hierarchy to begin their search for a successor.
Nagelsmann, who started coaching after a career-ending knee injury, became the youngest manager in Bundesliga history when he was appointed by Hoffenheim in February 2016.
He stayed there for three years, helping the club qualify for the Champions League for the first time in their history, before taking over at RB Leipzig.
Get the best features, fun and footballing frolics straight to your inbox every week.
Thank you for signing up to Four Four Two. You will receive a verification email shortly.
There was a problem. Please refresh the page and try again.