Silva said of Iwobi: "It's a matter of us (needing) to put him in his best physical condition possible. Of course we're trying to do it as fast as possible.

"It was a difficult week for him, which is normal. It was difficult the week before for JP Gbamin also. Just one week working with the team, but it is what it is.

"He's working really hard and well, like all the others, and it is up to me to decide whether or not he will be in the squad list for tomorrow."

Last weekend's clean sheet was Everton's ninth in their last 12 Premier League games and Silva is hoping they can make improvements at the other end as they look to better last season's eighth-place finish.

The likes of Iwobi and former Juventus youngster Kean have been brought in to that end, and Silva said: "Of course if you keep a clean sheet you are closer to win a football match, now we have to do the opposite in the other box: to be more clinical, to convert the chances we keep creating."

While Everton landed several of their major summer targets, they did not manage to sign another centre-back following the departures of Kurt Zouma and Phil Jagielka while they could not prise Wilfried Zaha away from Crystal Palace.

Silva said: "It's a different squad, I never said it's stronger and better. If it will be strong or not, we have to prove during this season. We signed good and important players but we lost really important players also. It is our goal and ambition to do better things this season."

The expectation from fans will certainly be that the Toffees can force their way back into the top seven, and perhaps even higher, with home form crucial.

They won their final four home games of last season and Silva is looking for a strong start against his former club on Saturday.

"It's really important for us to make Goodison our fortress," said the Portuguese.

"We finished really strong last season at home, playing well, fantastic the connection with our fans. Demanding from ourselves, giving them what they expect.

"We are really confident. I felt our players during the week worked really hard again with that enthusiasm to come and to play a football match at Goodison with our fans and to get the three points."

With Idrissa Gana Gueye having left the club, Silva reiterated that Schneiderlin will not be allowed to depart, but the likes of Kevin Mirallas and Oumar Niasse could yet leave Goodison.

"Kevin, Niasse and some of the other players, the market's still open to them and possibly something can happen," said the Everton boss. "They are our players but they want to play football and the space to them in our squad is not enough."

Silva hopes new signing Fabian Delph will be fit enough to return to training next week following a thigh injury.