Those are the thoughts of Sky Sports’ tennis commentator Barry Cowan.
Federer and Zverev have been drawn together alongside Marin Cilic and Jack Sock.
Cowan was asked to pick which game he is most looking forward to watching at the tournament and selected Federer’s clash with Zverev.
He believes the 20-year-old German is able to cause the Swiss legend some problems.
“I think Zverev will rise to the occasion in London,” Cowan said.
“The match between those two will likely decide who wins the group.
“It will be interesting to see how Zverev fares against Federer.”
In the other group, Group Sampras, World No 1 Rafael Nadal is joined by Dominic Thiem, Grigor Dimitrov and David Goffin.
Cowan believes Roger Federer has an easier ride than the Spaniard and has backed him and Zverev to qualify for the knockout stages.
“I actually think Federer’s group is weaker,” he added.
“Zverev has enjoyed a fantastic year and he will rise to the occasion in London.
“I think he will go through along with Federer. The match between those will decide who wins the group.”