The pair are joint leaders of the group after taking six points from their opening two matches of World Cup 2014 qualification, with La Roja beating Belarus 4-0 last Friday and Les Bleus falling to a 1-0 friendly defeat to Japan.
But the former Real Madrid coach is not reading too much into the latter of those two results and pointed out France's evolution on the back of Euro 2012.
"They've made some substantial changes, particularly to the backbone," he told reporters at a press conference.
"The flanks and people up front are the same, but the strong men in central defence and midfield have changed.
"There will be 15 points left to play for after the match, but the two games against France may be vital. It looks like one of us will qualify outright and that makes the game a cup knockout which needs to be settled."
Del Bosque also revealed that defender Sergio Ramos was not certain to be available for the encounter after picking up a knock, but stressed that "he would play if he's fit".