Managing director of football Fabio Paratici and director of technical performance Steve Hitchen are working hard before the deadline to improve the squad.

Nuno said: "It's easy to understand. While the transfer window is open, we have to be very, very aware of that.

"Because sometimes you have to react, sometimes you have to act.

"When I say act, our squad is talented and quality but we have to balance and there are positions that have to be well-balanced in terms of what we look for all the year.

"We have to realise anything can happen in football, anything.

"The squad needs balance. We have a very talented squad but needs to be balanced. We know, everybody knows, Fabio and Steve are working very hard.

"But like I say, it's always hard to improve something that is good.

"We have to be really, really accurate on the players we bring because have to bring things that we believe can make us better and stronger.

"It's not easy because we have quality players with us."

Winger Gil arrived at the club in midweek following his exploits at the Olympics, where he won a silver medal with Spain.

He could be involved against Manchester City, but has impressed Nuno either way.

"He's young, very talented. We saw him before we brought him but very talented player," the Portuguese added.

"Very good one-v-ones. He needs time. He needs time not only because of his age but the way he plays football.

"He's going to face the toughest competition in the world in the Premier League, where are the best players, the best defenders. So it's going to be hard.

"We're here to support and help him and find the best solutions for the team. But very talented player."