The 29-year-old is still hopeful of progressing to the last 16 despite two opening defeats and says the dark horses in the group are the Partenopei
The Italians travel to France for the Group F encounter on the back of a 2-0 defeat to Roma in Serie A, but have made a promising start to the season, having invested heavily in the summer buying the likes of Gonzalo Higuain, Dries Mertens and Jose Callejon.
Marseille, meanwhile, are a fifth in Ligue 1, but have yet to make their mark in the Champions League having lost their opening two games, and Valbuena says despite not knowing a lot about Tuesday's opponents, they will be in for a difficult match.
"Yes. It is a very difficult group, but it's not impossible either. We beat Dortmund in the last game [of the 2011-12 group stage] which allowed us to qualify, along with Arsenal," he told Uefa.com.
"We know these teams very well, especially Arsenal because a lot of French players and they have a French coach.
"The unknown team are Napoli but looking at their recruitment and investment, they're a big team."
Having been released by Bordeaux for being too small at the beginning of his career, Valbuena dropped to the fifth tier of French football to play for amateur side Langon-Castets.
The move helped Valbuena appreciate the importance of hard work, determination and passion for football, which he believes is reflected in the city of Marseille and his current club.
He added: "Football is like a religion at Marseille. That is why I didn't take things for granted: I worked a lot harder to succeed at such a demanding club. Somehow it brings a lot of positives. And it makes me want to push my limits even further."