Dortmund, who boast Egypt striker Mohamed Zidan, recovered from a poor start to their season to move up to fifth before the league's winter break.

Their 1-0 home victory over Freiburg extended their unbeaten streak to 10 games. Only five points separate them from leaders Bayer Leverkusen.

"If we can sign one or two players we will have good chances to finish second or third," Klopp was quoted as saying by German newspaper Bild.

"But we must bear something in mind: Mario Gomez joined Bayern Munich for 34 million and their striker Luca Toni earns as much as 15 Dortmund players."

Limited transfer funds did not prevent Dortmund from signing quality players though, with Argentinean striker Lucas Barrios impressing following his close-season arrival from Chile's Colo-Colo.

Barrios, who forges a fine partnership with Zidan upfront, scored nine goals so far, just three behind the league's top scorer Stefan Kiessling.

Dortmund won the last of their six Bundesliga titles in 2002.