Graeme Souness could follow up his swoop for German defender Sebastian Pelzer with a move for his team-mate Rainer Hauck.
Pelzer, 21, signed a two-year deal with Rovers last night after a 370,000 switch from Bundesliga side Kaiserlautern.
Hauck had a short trial at Ewood last month but it is not certain whether Souness will follow up his interest.
The Blackburn boss is also keeping an eagle eye on Chievo striker Bernardo Corradi but Rovers will face stiff competition from Inter Milan, Anderlecht and Manchester City.
Meanwhile, Blackburn have confirmed a three-date pre-season tour of Austria and Germany.
Rovers tackle Austrian amateurs Sportsunion Abtenau on July 26 before games against German teams Nurnberg (July 30) and FC Amberg (Aug 3).
Blackpool provide the opposition at Bloomfield Road on August 6 before Lazio visit Ewood Park three days later.
Blackburn already face three fixture changes in September.
The home games against Leeds (Sept 21) and Spurs (Oct 5) will be played a day later due to Rovers’ UEFA Cup commitments.
The Premiership game at West Brom, scheduled for September 28, will go ahead 48 hours later after Sky chose the game for live TV coverage.
Blackburn have pencilled in September 19 and October 3 for their first and second leg dates. The draw will be made in Monaco on August 30.