The 24-year-old plays for Arsenal in the role once filled by former France captain Vieira, who is now past his prime and not in national coach Raymond Domenech's squad for the June 11-July 11 finals.
The similarities do not stop there.
The same lanky figure, same ability to capture the ball and roll it up the field with calm authority, same discreet but determined manners: the two are much of a kind.
Diaby, who was called up for the first time in 2007, has won just two more caps since, the latest a 2-1 warm-up win over Costa Rica on Wednesday, in which he beautifully set up Mathieu Valbuena for the winning goal.
"I haven't played much, it's true, but I was called up many times," Diaby, a man normally happy to let his football do the talking, told reporters at France's training camp in Tunisia.
TWO REASONS
Diaby, who has stepped up a gear this season with a string of convincing performances for Arsenal that earned him warm praise from manager Arsene Wenger, has two reasons to believe he is likely to feature in Domenech's plans in South Africa.
One is that fellow holding midfielder Lassana Diarra, a good friend, was ruled out of the World Cup by illness a week ago and has not been replaced in the squad.
"It's tough for Lass because we're really close and were looking forward to living a great adventure together but his misfortune has helped the group bond," Diaby said.
The other reason is that Domenech has been trying out a new, 4-3-3 formation instead of his preferred, more defensive 4-2-3-1 system, and the change suits Diaby perfectly.
"I like that system better, especially if I don't play in front of the defence but rather on the right or left side (of midfield)," Diaby said.
Whether Diaby becomes an automatic starter remains to be seen but he says he will be happy whatever happens.
"I'm proud just being part of that group. There is a great atmosphere and, although I don't talk much, I get on really well with everybody.
"Of course I'd rather play a lot but if I don't, I'll accept it and I'll do my best to help out. The most important thing is not for me to play, it's for the team to win."
