Cameron Norrie needs to "take risks" when he faces the "ultimate challenge" of playing Novak Djokovic in the Wimbledon semi-finals, says Tim Henman.
Briton Norrie, the ninth seed, faces defending champion Djokovic on Centre Court not before 14:30 BST on Friday.
The 26-year-old had never been beyond the third round of a Grand Slam until this year's tournament.
"It's a two-horse race. Djokovic is the heavy favourite but Cam's always got a chance," Henman told BBC Sport.
"We've seen these upsets in the past and, fingers crossed, Cam can provide one of the biggest upsets."
The winner will face Nick Kyrgios in the final on Sunday after Rafael Nadal withdrew from the tournament because of his abdominal injury.
'Huge opportunity' for Norrie
Norrie reached the top 10 in the world in April having won two ATP Tour titles this year, while top seed Djokovic is seeking his fourth Wimbledon title in a row and seventh overall.
BBC commentator Henman, a four-time Wimbledon semi-finalist, had Norrie on the team when he was Great Britain captain for the 2020 ATP Cup in Sydney.
At the time, Norrie was ranked 52 in the world and had yet to win an ATP Tour title. He's won four since the start of 2021, including the prestigious Indian Wells tournament in October.
Looking back to the ATP Cup, Henman said: "He was progressing in the right direction, a great work ethic. But if you had said to me then that he's going to win multiple times on tour, win a Masters 1,000, and then he's going to be in the semis of Wimbledon, I wouldn't have necessarily believed you.
"I think that is testament to his work ethic, how much his game has improved. Not only has his game improved but his overall belief. Now he's been in the top 10, this has been another huge milestone having not been past the third round of a Slam. It's a huge opportunity for him."
Former world number four Henman says that Norrie is "such a great role model for the younger players" because of how he's worked to make the most of his talent.
"Success is about maximising your potential," he said. "When you look at what Cam's doing there is no doubt he really is maximising his potential."
Both Norrie and Djokovic had to come through five-set matches in their quarter-finals, with the Briton outlasting David Goffin and the Serb coming back from two sets down against Jannik Sinner.
Henman believes Norrie's "awkward" game and "relentless" approach can cause problems for the 20-time Grand Slam champion.
"He's a left-hander to start with, the variety in his serve is there and he's got two massively contrasting shots from the back of the court - he's got this heavy, really grippy topspin forehand and an incredibly flat, effective backhand," he said.
"Then you throw in his athletic ability, his movement. He's able to run all day, he makes few unforced errors from the back of the court. He's just a really tricky customer to play against.
"Without Roger Federer being here, Djokovic is certainly the best grass-court player in the world. I think it's the ultimate challenge at Wimbledon to play Djokovic.
"Norrie's got to take risks. He's got to look to be aggressive because we know that Djokovic has a lot of the same traits. It's the toughest test on a grass court over five sets but Cam has got nothing to lose and a lot to gain."
'Back yourself, embrace the occasion and use the crowd'
Tim Henman lost 6-3 4-6 7-5 6-3 to Pete Sampras in the 1998 Wimbledon semi-finalsHenman made the Wimbledon semi-finals in 1998, 1999, 2001 and 2002, losing to Pete Sampras over four sets in the first two before the three-day five-set epic against Goran Ivanisevic and finally a straight-set loss to Lleyton Hewitt.
When facing Sampras, who finished his career with seven Wimbledon titles, Henman was the underdog but said he "backed myself" and that it is crucial that Norrie does the same.
"It was a big step up, probably the most intense match of my life at that stage because it's magnified - you're a British player playing at home and we hadn't had a British player in the semis in the men's since 1973," recalled Henman of his first semi-final.
"I was the underdog but I backed myself. I was playing great tennis and these were great conditions for me. It was my favourite tournament, my favourite court to play on, so I had 100% belief that I could go out there and win that match. I think it's important that Cam definitely has that belief even though it's probably the toughest test on a grass court."
Henman believes it will help Norrie's chances if he involves the Centre Court on Friday.
"One of the elements that Cam's got to use - and he did it well against Goffin - is the crowd," he said.
"Not only can it give him a big boost but we've seen that it can get under Djokovic's skin. That's going to be an important 12th man for Norrie."
What would his final word of advice be for Norrie?
"Just embrace the occasion," said Henman. "To be in a Slam semi, playing at home at Centre Court at Wimbledon, go out there and enjoy it and give it your best shot and believe that you can do it."