Pochettino says Dele Alli's hamstring injury has come at the "worst moment" after he joined Harry Kane on the treatment table until at least March.
Pochettino's stretched squad, which is also missing Son Heung-min to international duty, has further highlighted the club's lack of transfer activity in the last two windows.
The Argentinian has reiterated that the club are open to making additions in the next week, but again warned of the difficulties.
"Our idea is always I'm so open to improving the squad and adding players, with Harry Kane and Dele Alli fit or not fit," Pochettino said. "It's so important to have a clear message to everyone.
"I was always open. I was open in the summer, I'm open now, but the different thing is the reality and it's difficult for us to add players that can help us or improve our squad. We're open.
"It's not that now because we suffer some injuries we're going to change our strategy. It's so clear.
"Always we were so open to finding the right profile and the right players to arrive and improve us. But we're working. We'll see what happens until the end. But we were always open to improving the squad.
"I think this transfer window is always the most difficult transfer window and you know very well because I'm seeing you every day, there are not too many transfers, with a lot of loans.
"It's difficult to find the right players for all the clubs. Of course we're Tottenham and to find the right profile to help us I think is going to be difficult. But we're trying, we're trying to deliver something."