He quickly tried to make up for that lack by trying to play Marcos Alonso, but there was a bit too much weight on his pass and Liverpool keeper Alisson Becker was able to react quickly enough to make the save.
It was Pulisic that Lukaku was looking for as half-time approached, but his brushed pass was easily cleared.
In the first five minutes of the second half, Alonso fired wide past a Pulisic cross, then the former Borussia Dortmund star squandered another great chance by sending a weak effort way too close to Alisson, who saved easily.
Like too many Chelsea forwards, Pulisic is not clinical. He can score brilliant goals and produce moments of real promise, but few people would bet real money on him hitting the back of the net when a big opportunity presents itself.
Alisson didn’t even have to make a save on another good chance in the 68th minute, when Pulisic sent his effort wide again after being set up by James.
It appeared that Tuchel might have run out of patience with his missed chances with five minutes of regulation time remaining, when Pulisic’s No.10 was displayed as Hakim Ziyech prepared to continue.
But it turned out that a mistake had been made and Pulisic’s number was changed to Lukaku’s, who walked away and Pulisic was moved down the middle to take a false position of nine.
There he remained Chelsea’s biggest threat, his pace causing a problem for Liverpool’s high defensive line. It was a boot from Trent Alexander-Arnold that stopped him trying to return Ziyech’s cross in the first half of extra time.
It turned out to be Pulisic’s last goal, as he was eventually replaced by Ruben Loftus-Cheek for the second half of extra time. He didn’t look particularly happy as he shook his head and watched the pitch from the bench, but father Mark can’t complain his son didn’t have more than enough time.