Isco insisted Real Madrid are just as competitive as last season despite watching the Spanish and European champions' stuttering campaign continue Saturday.
La Liga title-holders Madrid missed the chance to close the gap on leaders Barcelona to six points after a frustrating 0-0 draw at Athletic Bilbao.
Captain Sergio Ramos was sent off as Cristiano Ronaldo and Toni Kroos wasted opportunities at San Mames.
Ronaldo had previously suggested Madrid are not as strong in 2017-18 following the departures of Alvaro Morata and James Rodriguez, however, attacker Isco did not buy into the argument post-match.
"It's taking advantage a bit, when the results aren't coming, to say that the squad is weaker," he said.
"Our squad is just as competitive as last year, and we haven't had all of the squad available yet because of injuries and that's important."
The result, Madrid's second scoreless draw in three league games, saw Zinedine Zidane's men drop to fourth in the La Liga standings, two points behind rivals Atletico Madrid and eight adrift of Barca.
Casemiro said: "We had a chance to cut points and we played well. We had a lot of opportunities, but it's football, the ball didn't want to go in.
"But when it does, it won't stop, so we have to keep working."
