Isak came on after halftime in the Premier League match in London on Saturday night.
The goal in the 57th minute was his third – his second in the league – for Liverpool, but not one he got the chance to celebrate.
At the moment of the shot, Isak was brutally tackled by Tottenham defender Micky van de Ven.
Isak's left leg was pinched and the striker remained on the field, in pain.
He hid his face in his shirt while receiving treatment from Liverpool's medical team. Isak stood up and was able to stand on both legs, but he limped as he left the pitch with the help of Liverpool staff.
“Wait and see”
According to Viaplay, Liverpool manager Arne Slot could not provide any information about the degree and extent of Alexander Isak's injury.
"We'll have to wait and see," says Slot.
"It's hard to know what it is, but hopefully he's okay and let's hope he's back soon," Slot told Sky Sports.
The recent Ballon d'Or winner has had a tough start since his sensational arrival at Liverpool last summer. Isak wanted to leave Newcastle at all costs despite being under contract.
Newcastle punished him by not allowing him to participate in group training or play friendly matches. When the clubs finally reached an agreement at the end of August, the Swede became the most expensive player of all time in English Premier League football.
The price tag is said to have landed at around 1.6 billion SEK.
Isak's replacement Jeremie Frimpong set up Hugo Ekitike for Liverpool's 2-0 goal. Despite being one man down after Xavi Simon's early sending off, Richarlison managed to reduce the deficit at the end.
Heated match
Tottenham, who are still missing Swedish midfield star Dejan Kulusevski, did not come any closer.
The match was marked by a hostile atmosphere and poor discipline, especially in Tottenham. Cristian Romero received his second yellow card and the team's second sending off in added time.
Lucas Bergvall, Isak's national team colleague, played from the start for Tottenham but was substituted after 71 minutes.
"We showed strong character and fought until the end, but unfortunately it didn't give us any points today," he tells Viaplay.
