The Lions head to Blackburn knowing the winners of their replay will face Wigan - rather than Manchester City, Manchester United or Chelsea - for a place in the final.
The two Championship sides fought out a goalless draw in the original tie at The Den on Sunday and then learned which ever gets through had dodged the Barclays Premier League big hitters.
"Relatively speaking it's a good draw, for Blackburn and for Millwall," admitted Lions boss Jackett.
"We've got more chance against Wigan than, say, against one of the Manchester clubs. But when you get into this territory people play above themselves, it's such a big chance. But the draw is appealing.
"But I didn't really look at it. I was only thinking about the Blackburn game and if I'm truthful the next league game against Charlton as well."
Millwall have already won at Ewood Park this season, 2-0 in November, although their league form has taken a dive since then.
They also had the better of Sunday's stalemate but Jackett is taking nothing for granted.
"We have respect for Blackburn. They have a lot of Premier League experience and big-game experience and my focus is on matching that.
"As a club we have come from the opposite end. They are learning how to deal with coming down from the Premier League. We've come up from League One and are trying to maintain the momentum of our club.
"Our form has fluctuated a lot recently and I've been disappointed with that. But we played well on Sunday and we want to repeat that."