The left-back has been a key member of a Atletico side that has moved to the top of La Liga and into the quarter-finals of the Champions League.
However, his place in Luiz Felipe Scolari's squad, which will be named on May 7, is far from secure.
"If I said I was happy about not being called up, I'd be lying," he told FIFA.com.
"I'm pretty sure Felipao has more or less got the squad picked in his mind, but I'm going to keep on fighting till the end to make that list.
"Obviously I'm still available and I'm itching to hear some good news."
Luis has just four international caps to his name.