Atletico won their first La Liga title since 1996 last term, in addition to reaching the final of the Champions League.
"It's too early to say. What we achieved last season will raise the performance of the players and the aims of the team," AS reports the midfielder as saying.
"You have to compete with the best but it's increasingly difficult because our rivals have reinforced well. But our enthusiasm is still to be on top.
"I see every day more encouragement and people can be as happy as last season. We face a beautiful season. I'll follow the line of the team. Every day I feel better and I can contribute more to both the group and on the pitch."
Gabi signed a new deal with Atletico this summer.