With Martinez in her corner, Muguruza will play Venus Williams in Saturday’s final after crushing Slovakia’s Magdalena Rybarikova 6-1, 6-1 in the last four on Thursday.
Martinez became the only Spanish woman to win Wimbledon when she defeated Martina Navratilova in the 1994 final and now she is back in a key role at the All England Club as Muguruza’s temporary coach.
With Sam Sumyk, Muguruza’s regular coach, missing Wimbledon due to his wife’s pregnancy, Martinez offered to assist the 23-year-old.
Their partnership has proved an instant hit as Martinez, who also coaches Spain’s Davis Cup and Fed Cup teams, helped guide Muguruza back to the final two years after she lost to Serena Williams.
“I think she’s helping me to deal with the stress of the tournament, because it’s a long tournament,” Muguruza said of her 45-year-old compatriot.
“I’ve been here a while already. So she just knows how to prepare, how to train, what to do.
“Not that I’m doing something different, honestly. But to have her by my side gives me also this little confidence on having someone that has won before.”
Muguruza is the first Spanish woman to reach more than one Wimbledon final since Arantxa Sanchez Vicario, who lost twice in the 1990s.
Fittingly, it is Venus who lies in wait for Muguruza as the American star is the oldest Wimbledon finalist since Navratilova was beaten by Martinez 23 years ago.
Martinez’s calming influence has been ideal for the emotional Muguruza, who also remains in phone contact with Sumyk.
“Conchita and Sam are really working together. They are in contact. Before I do something, they both decided. So that magic is still happening.
“I think I’m here because I’ve been working not only the last few days, but longer time, getting ready for this kind of moment.
“I think a lot of things are clicking also with her and the team this week, so it’s very nice.”
Since winning her maiden Grand Slam title at the French Open last year, Muguruza had endured something of a sophomore slump as her ranking dropped out of the top 10.
But she has rediscovered her mojo on grass and would climb into the top five if she wins Wimbledon.
To do that, she must emulate Martinez and stop another Williams name being etched onto the trophy.
“All the names that I read on the honours board, I know all of them. For the last years, you see a lot of Williams surname,” she said.
“So I look forward to putting a Spanish name back there.”