During his pomp as the first tennis player to be fêted as a cross between a pop star and a Viking god, Björn Borg’s default setting was always flatliner calm, so it was a surprise to hear him in such demonstrative mood. A man who fell out of love with tennis at 26 and was considering selling his Wimbledon trophies this year has had his excitement rekindled — and the reason is Andy Murray.

Since he hung up his headband for the first time in 1983, the Swedish legend has kept a low profile, concentrating on an often awkward private life that has involved two divorces, a stomach pump and near financial meltdown. Now he is coaching young players in Sweden again and is enamoured by the Scottish prodigy.

“I have seen him quite a lot and I like what I see,” Borg said, after picking up a Lifetime Achievement award at the BBC Sports Personality knees-up on Sunday evening. “He has the heart for it and wants to be the best. I think he might be the next [world] No 1 player.”

Coming from Borg, a quiet figure not prone to outlandish predictions, it was a ringing endorsement. While conceding that Roger Federer, the present No 1, is a phenomenon, Borg believes that the combination of Murray’s game and his John McEnroe-esque volatility makes him a genuine challenger.

“He is the player that tennis needs — both British tennis and global tennis,” Borg said. “He has the personality that makes him the kind of person people want to see on the tennis court. It is especially good for British tennis to have somebody like that because a lot of kids will follow him.

“It is good that he makes noise on the court because it would be boring if everybody was the same. In my time, we had Jimmy Connors and John McEnroe and there was always something happening. That was good for tennis. It is difficult to compare Murray to any of the players I played against, but he doesn’t have any weaknesses and it is important that you can play on all kinds of surfaces. And he is still very young. I would not be surprised if he became a Wimbledon champion. He could make the top ten next year, for a start.”

It was good to hear Borg in such enthusiastic mood, given that it took a phone call from McEnroe, his one-time nemesis, to dissuade him from selling his trophies for £500,000. “When he called me and wondered what I was doing, I guess I woke up,” Borg said.

“Murray is going to be interesting to follow in the next year, especially in the grand-slam tournaments,” Borg said. “He needs to build up a little bit physically, but the main area he needs to improve is the mental one.”

Borg’s mental strength always highlighted McEnroe’s quivering bottom lip and angst-ridden tantrums, giving his remarks heightened significance. “Look at what he [Murray] did this year — he got some great results and improved his ranking greatly,” Borg said. “Brad Gilbert [his coach] has a lot of experience and knowledge and he can add a lot to Murray’s game, too.”

The trouble for Murray is that Federer is redefining tennis with his artistry and ruthlessness. “Federer is unbelievable and as long as he stays motivated, it will be hard for everyone else,” Borg said. “He wants records and has a great chance of breaking mine [five successive Wimbledon titles]. Modern tennis is good. I like to see Federer and [Rafael] Nadal play because they have such different styles.”

Borg said that he is enjoying his life in Sweden and his brief foray into the spotlight, in front of an audience of 4,000 at the NEC in Birmingham, did not come naturally. Nevertheless, with a renewed hunger for the sport he once bestrode, he suggested that he might be willing to extend his stay. “If the LTA rang, I don’t know what I’d do,” he said. “Who knows?” Whether selling history or making it, Borg remains big news and the idea of him working for the LTA is a lip-smacking one that ventures beyond nostalgia. But having bought back his trophies from Bonhams, the auctioneer, he seems happy with his lot and his place in the pantheon of greats.

Before the 11 grand-slam titles, it is worth noting that he won his first ATP tour title aged 17 years and 11 months. Murray was 18 years and nine months, Federer 19 years and six months. “He [Murray] is young, but he already has the ability,” Borg said. “And you can tell he wants it.”

The two teenage prodigies

Bjorn Borg

Born: June 6, 1956

Style: Iceman

Achievements at Murray’s age: Made his Davis Cup debut for Sweden at the age of 15 and won the Boys’ title at Wimbledon a few months later. In 1973, he reached the Wimbledon quarter-finals at his first attempt. At 17, won his first Tour title and then his first grand-slam title, the French Open. Repeated the feat the next year and helped Sweden to win the Davis Cup. Began his Wimbledon dominance in 1976.

Andy Murray

Born: May 15, 1987

Style: Tetchy

Achievements: Will finish 2006 as the world No 17. His breakthrough came last year, when he made his Davis Cup debut for Great Britain at 17 and reached the third round of Wimbledon. This year he beat two former world No 1s, Andy Roddick and Lleyton Hewitt, to win his first Tour title, in San Jose, California, and beat Roger Federer, the present No 1, in Cincinnati. Reached fourth round at Wimbledon and US Open.