Speaking during his press conference ahead of Sunday's La Liga game with Real Valladolid, Los Blancos head coach Carlo Ancelotti revealed that Bellingham was a doubt for the team's next game, having suffered "a knock" during the morning training session.
Real Madrid have now released a statement confirming a problem with the midfielder's right leg, and it is believed that he will be on the sidelines until the end of September due to the nature of the damage.
"Following tests carried out today on our player Jude Bellingham by the Real Madrid Medical Services, he has been diagnosed with an injury to the plantar thin muscle of his right leg. Pending evolution," read a club statement.
Los Blancos have not provided a timeframe in terms of a recovery, but journalist Mario Cortegana has reported that he is unlikely to be available for the month.
Real Madrid confirm Bellingham injury issue
Bellingham could miss Real Madrid's next six league games, potentially returning to action at the end of September against Atletico Madrid.
The 20-year-old was the capital outfit's star player last season after arriving from Borussia Dortmund, scoring 23 goals and registering 13 assists in 42 appearances.
However, Bellingham will be playing in a deeper area this term due to the arrival of Kylian Mbappe.
The England international provided the assist for Mbappe to score in the UEFA Super Cup on August 14, but he could not help his side overcome Mallorca in La Liga last weekend, with the points shared in a 1-1 draw.
Eduardo Camavinga and David Alaba are also still absent for Real Madrid, with the latter continuing his recovery from a serious knee issue and the former set to be out until after the September international break.
Which player could benefit from Bellingham absence?
Luka Modric will naturally be the favourite to replace Bellingham in the XI, with the Croatian potentially slotting into the midfield alongside Aurelien Tchouameni and Federico Valverde.
The 38-year-old signed a new one-year deal at Bernabeu over the summer, and he demonstrated last season that he remains one of the most productive central midfielders in world football.
Dani Ceballos is also an option, with the 28-year-old staying at Real Madrid this summer despite a host of speculation surrounding his future earlier in the transfer window.
Ancelotti could also potentially introduce Arda Guler into a central position, but that change would lead to a tweak in the manager's 4-3-3 system which he has implemented early in the campaign.
Modric is likely to be the player to benefit against Real Valladolid, but due to the quick turnaround, with the next game coming against Las Palmas on August 29, it would not be a surprise to see Ceballos or Guler in the XI in the near future.