Frank revealed that defender Destiny Udogie would be out until January after picking up a hamstring injury at the end of the Newcastle game last week.
He said Brennan Johnson is "touch and go" after missing training on Monday.
Midfielder James Maddison returned to training on Monday but Frank said it will still be "a long time" until he's fully fit: "It's very early stages, still a long term injury. Good to see him out there, but no specific time frame."
The Spurs boss also revealed that there is an internal investigation into midfielder Yves Bissouma, who was recently filmed inhaling nitrous oxide: "It's an internal matter we are dealing with at the moment."
On following the weekend win over Brentford: "It's always good to build momentum, to get more consistent performances. We will try to build on that tomorrow night, we have a good opportunity against a Slavia Prague side who are very direct and physical, man mark all over the pitch. That can particularly make it difficult for us. It is about us making sure we perform well, with forwardness and directness in attacking play."
When asked about back-up keeper Antonin Kinsky, who joined from Slavia Prague last season, Frank said: "Toni is a very good goalkeeper, he has a great future ahead of him. It is difficult for any player, if you are not playing you are not 100% happy. You just need to keep your head down and keep training every day."