Xisco saw signs of improvement during last night’s 1-1 draw with Middlesbrough but agreed his side must maintain high levels throughout the 90 minutes.
Wednesday raised the bar in the first half, taking a 1-0 lead into the break, before Boro wrestled back control in the second and duly levelled.
Xisco said: “I saw some good signs in the first half, we showed we have the levels. Middlesbrough came back into the game in the second half and that left me disappointed because you have to kill teams off when you are in control or football will kill you.
“We have to find more balance because when the two halves are so far apart it's very difficult to analyse the game. The first half and the second half were black and white.
"We need to do it with mentality, with personality, with tactics and physical conditioning. We have to improve these things.
“I know what I can improve in this team and most importantly I believe in these guys. I will give everything for these players and I have the belief.”
Meanwhile, the Owls boss confirmed he is assessing the merits of striker Lyle Taylor as he looks to strengthen in the final third.
The former Forest man is currently unattached and training under Xisco’s watchful eye at Middlewood Road.
He explained: “Lyle is training with us, and after that, we’ll decide if he’s going to continue with us or not.
“Right now, he’s an option and we’ll evaluate whether he can give something special for the team and help the squad. He’s the sort of player that can give something different.”