The 48-year-old has voiced his disappointment with his side's 1-0 loss as he feels they proved to be at least as good as their opponents
A single Jonas strike in the opening 45 minutes proved to be too much for the youthful Ligue 1 side, but Garcia was nonetheless satisfied with his side's performance.
"We were a bit tentative in the first half; the second was better. The tempo was too slow before the break, but Valencia didn't really conjure up any meaningful shots - that is why a defeat is so harsh. Unfortunately, their goalkeeper made two or three top-class stops," Garcia said at a press conference.
"The players always give their all. I knew we could make the team more technical with our substitutions, and what we did in the second half we should have done in the first.
"Now we must focus on the league and cups. We would have liked to have given our fans the points; they deserved it."
Lille resume Ligue 1 action on Saturday when they travel to Sochaux.