The Spain midfielder was sent off after just 29 minutes, as La Real eventually lost 2-1 on the night.
Imanol said: "First of all, I would like to thank the players and the fans for their efforts. The players have done everything possible, it is not easy to play for so long with one less player, but they have tried to create goal-scoring opportunities and defend, which is not easy, and also the fans, because I have seen a good atmosphere from the start and then they have been aware that the team needed them.
"I think that eleven against eleven we were better than them, we had a very clear chance of Take, and then, even with one less, we were able to get ahead, until the penalty I don't think they had any scoring chances. What happens is that at certain moments we lacked forcefulness and, if you don't have it, it's more complicated.
"Either you win the duel or the rival wins it, and many games in the Primera Division are decided by duels. The centre-backs have been charged with two yellow cards that were more than avoidable. It's not a question of tiredness or concentration, I insist that it's a question of power."