The 25-year-old midfielder played a key role in Dortmund's Bundesliga-winning campaign last term, making 37 appearances in all competition.
However, the improvement in many of Dortmund's youngsters has seen Blaszczykowski relegated to a reserve role this season.
With Euro 2012 on the horizon, Blaszczykowski, who captains Poland, one of the host nations of next summer's championships, admits he may consider leaving Dortmund should his current situation continue.
"I am not satisfied with the way I'm being used at the moment," Blaszczykowski told Polsat. "I get upset when I don't play.
"Let's just wait and see how things develop before December. Some things could change over time.
"When I don't get the chance to prove my worth, I might have to look elsewhere to get playing time."
Blaszczykowski has found it hard to break into the Dortmund starting lineup, especially with young guns like Mario Gotze, Shinji Kagawa and Sven Bender shining on a weekly basis.
His cause was not helped in the summer by the arrivals of fellow hot midfield prospects Ilkay Gundogan and Ivan Perisic, plus the return from injury of captain Sebastian Kehl.
Blaszczykowski, affectionately known as 'Kuba' to his fans, arrived at the Signal Iduna Park in 2007 from Wisla Krakow, and has made over 130 appearances for the club so far.