The rumor mill just can't stop churning with speculation about D.C. United defender Steve Birnbaum.
The latest rumblings, this time from FutbolMLS.com, say the 25-year-old center back has caught the eye of German club Borussia Dortmund.
Interest from the Bundesliga club is the highest-profile of the recent rumors attached to Birnbaum, but a report from MLSSoccer.com writer Greg Seltzer calls the rumors false, citing German sources who laughed off the speculation.
A spokesperson for D.C. United declined to comment on any of the recent rumors involving Birnbaum.
Previous reports have suggested Birnbaum attracted an offer from least one club in Europe, with clubs in Germany and Belgium showing some level of interest. Another report indicated that Maccabi Haifa in Israel had expressed interest in the defender. But reports out of the nation's capital also suggest D.C. United aren't willing to part with the defender, who still has two years left on his contract.
Birnbaum has played a prominent role for D.C. United since being drafted in 2014, but it appears his recent US national team appearances have triggered a rise in his stock. He played against Guatemala in the USA's World Cup qualifying win at home in March, in January he scored a game-winner against Iceland, and now he has made coach Jurgen Klinsmann's preliminary roster for the Copa América Centenario.