The Swedish striker had hoped to play for Hamburg at the weekend against Werder Bremen. But his three-game ban for spitting at Everton's Marco Materazzi also stands in Germany, so he must wait to make his debut.
Hamburg currently occupy fifth place in the Bundesliga but have managed to score just nine goals this season. They have agreed to pay a fee of pounds 900,000 to Blackburn if Dahlin makes the move permanent.
Bayern Munich said yesterday that they have fined their controversial midfielder, Stefan Effenberg, heavily after he was stopped while driving with more than twice the legal limit of alcohol in his bloodstream.