Mauricio Pochettino looking to test Chelsea's depth after failing to sign Michael Olise

The Crystal Palace winger turned down a move on Thursday in order to sign a new contract at Selhurst Park, despite Chelsea having activated a £35million release clause.

It leaves Pochettino's squad still seemingly lacking in attacking options, a problem made more acute by the knee injury sustained by new signing Christopher Nkunku in pre-season that is likely to rule him out until December.

The club are waiting for striker Armando Broja to make a long-awaited return from the ACL injury that has kept him out since the end of last year, and Pochettino said he would be reluctant to go into the market for a player that might limit first-team chances for the Albania international.

Academy graduate Broja played 18 times for the club last season before getting injured, scoring once in a 3-0 against Wolves in October, following a successful loan spell at Southampton the previous campaign where he netted nine times in 38 appearances.

Nicolas Jackson is currently the only fit striker available to Pochettino, with out-of-favour Romelu Lukaku having not been given a squad number and eager to leave before the September 1 deadline.

But after a transfer spree that has seen the club spend in excess of £350m during the current window - including the £53m capture of Southampton midfielder Romeo Lavia on Friday - the manager said that the current squad must sooner or later be made to show its flexibility.

"We're working of course, seeing all the options that we can manage in the market," said Pochettino. "All clubs are doing the same as us.

"I think at the same time we are keeping one or two eyes on Armando Broja because I think we can't forget him. We cannot stop him, and to bring some profile of player than can stop his evolution.

"We really believe in him. We know him very well. He can be a really important striker for Chelsea. We need to be careful.

"We're disappointed with the situation of Christopher because he should be a very important player for us, helping Nico Jackson to score goals. But that is football and we need to accept that situation.

"At the same time, we cannot go for some player that is going to stop a player that we have, maybe we need to be patient and try to adapt our squad to try to get results, waiting for Armando to be fully fit."

There are currently 28 first-team players that have been assigned squad numbers this season, though a deal for defender Lewis Hall to join Newcastle is understood to be imminent.

Defender Wesley Fofana is likely to miss much of the season after undergoing surgery on a cruciate ligament injury, but it still leaves Pochettino with more available players than he would like, indicating more departures are planned.

"This number - 22, 23 players - is perfect," he said. "This season we are not going to be in European competition, so I think (the number) is good.

"But maybe even if next season we are in Europe, I think it™s good also, to have the possibility to bring young guys through the academy to be involved and to show they can play for the first team."

Pochettino was asked for his response to the suggestion that some of his squad see him as more of friend than a manager.

"I am not happy with this," he said. "Tell me the names of the players, because there's something wrong if I am more friend than coach.

"No, I understand the situation. To be strong like a coach, in the same time you can be friendly. You can be honest and be tough, and in the way that we can approach today, all the young guys can be my kids.

"I think it's important to understand the psychology today of the players. In the past it was different, but now we need to learn, we need to see society how they are and to apply the ideas and the way to approach them in the way that you can get the best from them.

"I prefer to be a better coach than a better friend."

READ MORE: Why this could be Arsenal's year in Premier League