Gareth Taylor's side face the toughest of tests to progress to the semi-finals, needing to overturn a 3-0 deficit from the first leg, but Mewis asserts her teammates have full confidence in their ability to produce a sensational comeback.
A World Cup winner, the United States star has performed on the biggest stages, under the most intense pressure.
While the squad could be forgiven for heading into the clash wary, Mewis insists the vibes in training have been nothing but positive with the players intent on reaching their very best level of performance.
"The mood has been good," she declared.
"Everyone has been staying after practice. We all want to get better. It's a special group. I am really excited to get out there and fight for it.
"It's a great opportunity for everyone to come together and really bring their best.
"I am really optimistic. It is going to be hard. We really have to grind it out. We have what it takes to grind it out. We are pumped and fired up."
Watch Sam's preview in the press conference above...