British number one Andy Murray was relaxed about a groin niggle following his 6-3 6-4 6-4
Murray, who now plays in the last four, slipped on the baseline but said: "On the grass sometimes your feet get caught, but I feel alright.
"I'll get treatment for sure, but these things happen during Grand Slams and you've got to try to get on with it."
Of his win, Murray said: "It was good, I thought I served well throughout."
Lopez had beaten eighth seed Andy Roddick in straight sets earlier in the tournament and then came back from two sets down to beat Lukasz Kubot in round four, but Murray proved an altogether tougher test.
After reaching his third successive Grand Slam semi-final, the British number one said: "Feliciano looked a little tired and struggled a bit with his movement.
"I got off to a good start in all of the sets. That helps against someone like 'Feli' because he serves well.
"Normally against the big servers, they like to put pressure on you towards the end of the set. But because I got ahead early in all of them, I was able to dictate the points from the back of the court and played a good match."
Lopez conceded that Murray's consistency had been key to the Scot's quarter-final victory.
"He played unbelievable tennis - this is the main reason why I lost," said the Spaniard.
"He was very solid, no mistakes, serving great, unbelievable returns. At one point I didn't know where to serve because he was reading my serve very, very well."
Murray will have to produce more "unbelievable" tennis against Nadal on Friday given that he has won only four of his 15 matches against the Spaniard and in last year's semi-final lost in straight sets.
If Nadal has had the upper hand on the court, Murray quipped that the Spaniard was less dominant when the two players fought it out at PlayStation football.
"He actually isn't very good at PlayStation," revealed Murray, who said that Nadal and his PlayStation partner Juan Monaco always got to pick the best team to the disadvantage of the Scot and team-mate Danny Vallverdu.
"They play with Inter Milan and we're not allowed to play with Inter even though they're best team in the game," said Murray.
"Once the game starts, you're not allowed to make substitutions. It's just all their rules. So when we lose, we're a little bit like, 'Yeah, we blame the rules that they have'.
"I did play them once with our camera view and we won, but that's the only time we got a chance to play them."
Asked what the result would be if he played Nadal at singles football, Murray added: "It would be very comfortable for me, so they only play on a team."