Friday’s semi-final will be a repeat show of last year, where Alcaraz beat Russia’s Medvedev in straight sets on the way to his first Wimbledon crown.
The Spanish world number three came through 5-7, 6-4, 6-2, 6-2 against America’s Tommy Paul in the quarter-finals on Tuesday while Medvedev outlasted top seed Jannik Sinner 6-7 (7/9), 6-4, 7-6 (7/4), 2-6, 6-3.
Alcaraz, who leads Medvedev 4-2 in head-to-heads, said it would be tough to face the former US Open winner, picking out his ability to get the ball back in play.
“The most difficult thing about facing Daniil, or the most special thing about him, is he can reach every ball,” he said.
“Well, he is like a wall. Every ball bounces back. I feel like I can hit an unbelievable shot, the ball is going to bounce back.”
Medvedev, for his part, said three-time Grand Slam champion Alcaraz, 21, was a danger anywhere on the court.
Alcaraz said he was delighted that opponents feared him in such a way because it meant they had to “focus on every shot”.
“You know whatever shot you hit, he can hit a winner from there,” said Medvedev. “So you try to make his life difficult. You try to hit the shot as good as you can.
“Maybe he goes for it and he cannot make it. But that’s pretty special because there are not many players like this.”
The 28-year-old added: “Carlos can do whatever from any position and that’s not easy to play against.”