Britain's Cameron Norrie says facing six-time champion Novak Djokovic in Friday's Wimbledon semi-final is "one of the tougher tasks in tennis".
The 26-year-old had never made it past the third round of a Grand Slam before this year's championships.
Conversely, 35-year-old Djokovic has claimed 20 major titles and is seeking a fourth successive Wimbledon crown.
"It's going to be a tough one with his record here at Wimbledon," Norrie told the BBC.
"Obviously, grass is his favourite surface. I would say [it's] one of the tougher tasks in tennis."
Top seed Djokovic and ninth seed Norrie are due on Centre Court not before 14:30 BST, with the winner facing Nick Kyrgios on Sunday after Rafael Nadal withdrew injured from the other semi-final.