Dank was summoned this week by the Australian Sports Anti-Doping Authority to answer 34 allegations under its anti-doping code.
Dank and his barrister Greg Stanton are weighing up their next move.
Demetriou, who was briefed by his team this morning, said it was disappointing that something this significant would leak on the eve of the season.
"I think the timing's unfortunate because we've had a pretty clear few months. It does distract from what should be a great game tonight," Demetriou told Melbourne radio station ABC 774 on Friday morning.
Demetriou said Dank's summonsing was long overdue, and that the League had been notified by ASADA that its investigation would wind up in April.
When asked whether the latest issue would overshadow the season, Demetriou replied: "I hope not. It can't, because it's unfair to a game trying to derail the season."
"It's unfair to the Essendon Football Club, who are trying to do all they can to move on."
Meanwhile, Demetriou said it was "absurd" that the MCG is going unused this weekend.
Under existing arrangements, the Victorian Bushrangers cricket team has the right to play at the ground should it host the Sheffield Shield final.
As it turns out, the Bushrangers will not be playing in domestic cricket's decider, meaning the MCG remains vacant at the start of the AFL season.
The AFL has lobbied heavily with Cricket Australia to sort out the predicament, but negotiations have not been resolved.
The season starts on Friday night with the game between Collingwood and Fremantle at Etihad Stadium.
In recent years, Richmond-Carlton MCG blockbusters have kicked off proceedings.
"We've found ourselves in this conundrum where we find the MCG vacant this weekend," Demetriou told 3AW.
"It's sort of absurd that the MCG is not being used and it's not going to be used the next couple of weeks, with football being played elsewhere.
"It's absolutely more preferable to be playing a big game Thursday, Friday or Saturday night at the MCG in front of 85-90,000 people."
Twitter: @AFL_BenGuthrie
