The 21-year-old opened the scoring for Spurs in a 3-1 victory but his afternoon quickly turned from a dream to a nightmare.
Sarr was replaced by Oliver Skipp in the 32nd minute after undergoing prolonged treatment on the turf.
As Sarr left the field, he covered his faced with his shirt and appeared to be struggling with his emotions.
The Senegal star is expected to be a key player for his nation at the upcoming Africa Cup of Nations, which begins on January 13 in the Ivory Coast.
Sarr was an unused substitute as the Lions of Teranga beat Egypt to win the tournament in 2022.
READ MORE ON TOTTENHAM
Liverpool legend in disbelief as key Chelsea star linked to shock transfer
Tottenham announce Hugo Lloris exit as club legend completes move to MLS side LAFC
It is not yet clear whether the injury will affect his chances of competing as Senegal begin their defence against Gambia on January 15.
Captain Heung-min Son and manager Ange Postecoglou were among those who tried to console the stricken midfielder.
Spurs have been plagued with injury problems this season and the north-Londoners are currently without James Maddison, Micky van de Ven and Cristian Romero.
Meanwhile, Yves Bissouma was unavailable for the visit of Bournemouth due to suspension.
Most read in Football
Vinicius Jr travels 6000 miles for eight hour tattoo but fans notice glaring error
Why are you questioning me?' - Ferdinand in heated clash with Jenas over Man United 'bias'
Premier League done deals: Every completed transfer in 2024 January window
Salah to Toney, De Gea to Messi - the biggest deals in a potentially mega January window
The Mali international is also due to compete at AFCON in January.
Despite injury problems of his own, Sarr has played 18 matches for Tottenham in a breakthrough season, scoring two goals and grabbing two assists.