Harry Kane sustained an ankle injury in the FA Cup match against Millwall and will have a scan come Monday.
The England international rolled on his right ankle after a tackle from Jake Cooper five minutes into the game.
Kane left White Hart Lane on crutches and Pochettino says the injury is similar to the one he sustained earlier in the season.
“He twisted his ankle in the same way as before, it was the same ankle he injured in the game against Sunderland,” Pochettino said. “Now we have to wait, we will assess it tomorrow.
“It’s difficult. We hope it’s not a big issue but it looks a similar situation as his previous injury. We hope it’s not a big issue. I’m sure it will be difficult to play against Southampton next weekend.
“Of course I’m sad about Harry’s injury but we have to find a solution. When you lose a player like Harry you will miss him. Harry is one of the best strikers in England but we can’t cry.”