Former British number one Tim Henman believes Andy Murray is capable of besting the top eight players at the World Tour Finals.
The Scot opens his round-robin campaign against Spain's David Ferrer on Monday at London's O2 Arena.
"You can't really look that far ahead - about winning the tournament in the first few matches," said Henman.
"It's tough to bet against any of the top four guys, and I definitely fancy Murray's chances."
The Scottish world number three comes to London as one of the form players at the event having won three tournaments in a row on the Asian swing of the ATP tour.
However, the 24-year-old said on Saturday that from the first serve at the season-ending event.
Henman agrees, although he says Murray can afford to slip up and still make the semi-finals.
Also in Murray's group are the world number one Novak Djokovic and Tomas Berdych, the last man to beat the Scot.
"With this round-robin format, you can still lose a match and go through," Henman told BBC Scotland.
"The first match is always important and I think Andy's got a good draw to play Ferrer in his first match.
"So if he can win that it'll set him up nicely.
"He had a great run here last year. I think these conditions [on the indoor hard court] suit him well and it is a home tournament for him.
"So I'm sure he's got big expectations to finish the year off well."
Henman's gut feeling is that Djokovic will cap his amazing season with victory, although he points out reasons why the Serb and also Rafael Nadal could come unstuck.
"Djokovic has obviously been the form player this year," he added.
"But there are question marks over his form and fitness, especially with his shoulder.
"Nadal hasn't played a great deal coming into an event of this stature.
"Federer is playing as well as anyone and got a good win against Tsonga in his first match.
"But Murray's got a great chance."