Alexander Zverev must play aggressive tennis against Roger Federer at ATP Finals
Catch Zverev's mouth-watering clash with Federer live only on Sky Sports Arena & Sky Sports Main Event from 6pm on Tuesday night
Last Updated: 14/11/17 7:43pm
Barry Cowan and Leif Shiras believe Alexander Zverev must play an "ultra-aggressive" game in order to down Roger Federer in their crunch ATP Finals clash on Tuesday night - live only on Sky Sports.
German 20-year-old Alexander Zverev marked his debut at the season-ending tournament with a 6-4 3-6 6-4 victory over Marin Cilic on Sunday.
The world No 3, the youngest qualifier for the finals for nine years, will face a mouthwatering clash with Federer next with the winner almost certainly making it through to Saturday's semi-finals.
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Federer, who is aiming to win the ATP Finals for the seventh time in his career, had earlier beaten American debutant Jack Sock in straight sets.
And Sky Sports' analysts Shiras and Cowan are both looking forward to an intriguing meeting of different generations.
I expect both these guys to come and play, but I think Roger will get to a higher level
"Zverev is going to have to play better than he did against Cilic," said Shiras. "He started off pretty well and then really almost gave the match away, but it was Cilic who gave it to him and I'm not sure Federer will be as generous.
"I'm not sure Zverev's energy levels are up to the task because Roger is so good at being able to put the ball in places where guys can't get comfortable.
"Federer will be able to get Zverev in positions off the court where the forehand isn't doing as much damage and he won't be able to hurt him as much. It will be an exciting chess match, albeit, Zverev does bring an element of power and if he serves great, then it could be a tough day for Federer but he's going to have to do it over the course of three sets.
"I think Federer is the favourite, but I just think his energy levels are pretty good. He's been in this situation before, but round-robin is a different animal. I expect both these guys to come and play, but I think Roger will get to a higher level."
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Cowan feels Zverev, bidding to become the first German to finish the year in the world's top three since Boris Becker in 1994, will take it to the 36-year-old.
"What Zverev can do is go into the match with a clear game plan to be ultra-aggressive," Cowan said. "There's no thought in his mind at what could potentially he could lose.
"This is a wonderful opportunity for Zverev to showcase the huge talent he has. I'm with Leif in that they'll both play better, but subconsciously he will be thinking 'I need something for the last match in the round-robin'."
Leif Shiras and Barry Cowan were speaking to Sky Sports' Raz Mirza at The O2.
The season-ending extravaganza ATP Finals ends another memorable year which will be covered via our website www.skysports.com/tennis with live blogs, reports, reaction and expert analysis as the season reaches its climax.
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