Kane scored Spurs' Premier League winner against Sunderland on Sunday before picking up an ankle problem in the closing minutes, and was eventually stretchered off along the White Hart Lane sidelines.
"It's difficult without Harry Kane but that's why we signed Janssen and he's working well," Pochettino said.
"He's a striker who can give us a lot of things."
Regarding Kane, Pochettino added: "We will assess him [on Monday]. It was tough, he twisted the ankle."