Pope recorded yet another shutout as Newcastle earned a 1-0 win in the first leg of their semi-final tie against Southampton on Wednesday (AEDT), with Joelinton scoring a second-half winner before Saints had Duje Caleta-Car sent off.
While Newcastle dominated for long periods, Pope made two crucial saves to deny Che Adams when the game was goalless, the first an excellent one-on-one stop with his legs.
Pope has now kept 10 successive clean sheets across all competitions – a feat not managed by any other Premier League goalkeeper in records dating back to the start of the 2012-13 season.
Guimaraes reserved lofty praise for his team-mate after the win, telling Sky Sports: "I would like to say thanks for Nick Pope – he's been brilliant for us.
"I think he's the best goalkeeper, right now, in the world.
"We controlled the game but missed some opportunities which we cannot miss. But we are happy, it is just the first game. I'm proud of the team today."
Newcastle also had a late VAR review to thank for their clean sheet as former Magpies striker Adam Armstrong was ruled to have bundled the ball home with his arm, leaving Pope relieved.
"A lot of work goes into it. I've let one in and VAR has helped us out," the England international said.
"We're really happy with that aspect of our game at the moment. We look really solid at the back and the boys work hard to make that happen."
Newcastle have now kept 16 clean sheets in all competitions this season – more than any other team across Europe's top five leagues, and boss Eddie Howe was delighted with Pope's display.
"I can't be critical of the team in any way," Howe said. "I thought we defended well again, I thought Nick made a couple of really good saves near the end again.
"The two saves he's made are big saves in the game. Adams' one-on-one was at a huge time in the game when Southampton were beginning to get on top.
"Nick stood up for us and made a great save, and then he made one shortly afterwards as well. He's been outstanding for us this year. Whenever he's needed, he's produced the goods for us."
Howe was also asked about Newcastle's pursuit of Everton's Anthony Gordon, amid reports suggesting the Magpies are working on a deal worth £40million for the winger.
However, Howe insisted he was purely focused on guiding Newcastle to their first EFL Cup final since 1976, responding: "I can tell you absolutely nothing. I've been focused on preparing for this game for the last two days."