Mauricio Pochettino is unsure on the severity of the injury Toby Alderweireld sustained against West Brom but appeared to rule him out of their trip to Bayer Leverkusen.
The Belgium defender, integral to Tottenham's ultimately fruitless title challenge last term, was taken off on a stretcher 60 minutes into Saturday's 1-1 draw clash following an awkward landing.
And Pochettino - whose side face Bayer Leverkusen in the Champions League next time out - acknowledged that the Belgium international is unlikely to travel to Germany.
"With Toby we need to wait 24 to 48 hours," Pochettino said. "He got a heavy knock to his leg.
"We will see what happens, now it is very painful. We need to know the problem. It is very difficult for him to go [to Leverkusen].
"But we need to assess with a scan or whatever the doctors want to do. We need to be clear what happened in his leg. I don't know exactly what happened, it was hard for me to see from the bench.
"All I said was, 'How are you?' And he explained he had pain. It is a big area: knee, leg, all."
Dele Alli's late strike at the Hawthorns ensured that Tottenham remained the only unbeaten side in the league in 2016-17 after the opening eight matches.