First-team attackers Philippe Coutinho, Adam Lallana and Daniel Sturridge are all unavailable to Liverpool who are believed to have made a £24m bid for Shakhtar's Brazilian forward Alex Teixeira this week.
Klopp insists he was initially wary of conducting any major business in January, but now feels his hand has been forced by the club's mounting injury list.
"The whole situation changed obviously," the German manager told a press conference.
"I think I always said if our situation changed then we had to change our opinion. We have to watch the market, to think about what makes sense for us now plus for the summer. If we find a solution which fits for both transfer windows, winter and summer, and a player could help us as quickly as possible then of course we would try."
But Klopp also warned that doing business was made more difficult by the inflated prices often attached to players.
"The January window is not the best and if you are under pressure then everyone wants prices where you think 'Are they crazy?'" he said.
So far this month Liverpool have limited their transfer activity to the acquisition of centre-back Stephen Caulker on loan from Southampton and teenage midfielder Marko Grujic from Red Star Belgrade.