According to Sky, the German sides have been keeping a close eye on the Montenegro international as they assess options for the future.
Bulatovic joined Lens and remains under contract with the French club until 2030 after signing a new deal in February.
Any club looking to prise him away from Lens will have to make a significant investment. Sky reports that the French side currently want €25 million plus bonuses for the highly rated midfielder.
Bulatovic has already made 12 appearances for Montenegro at senior international level despite his age and is regarded as one of the promising young midfielders in Ligue 1.
His opportunities at club level have been more limited this season, however. Bulatovic has started one Ligue 1 match and made four further appearances from the bench.
He did start Lens’ Champions League meeting with Slavia Prague and played the full 90 minutes in the 3-2 victory.
The midfielder’s performances have nevertheless been enough to attract attention from two of Germany’s leading clubs.
Borussia Dortmund have a strong track record of recruiting young players with the potential to develop at the highest level, while RB Leipzig have also built their recruitment strategy around emerging talent.
Bulatovic’s long-term contract means Lens are in a strong negotiating position, particularly if interest from the Bundesliga develops into formal approaches.
The €25m valuation would represent a significant investment in a player who has only recently established himself at senior level, but his age and potential could make him an attractive proposition for both clubs.
For now, Dortmund and Leipzig are monitoring the situation rather than preparing a confirmed bid.
Bulatovic’s development at Lens will therefore remain important as both Bundesliga clubs determine whether to turn their interest in the Montenegro international into a concrete transfer attempt.