Mikel Arteta hinted at dissatisfaction with some players in his Arsenal squad as he suggested only "the majority" had given their all this season.
Arteta has endured a miserable first full campaign as Arsenal manager, having won the FA Cup at the end of last season.
Next term, for the first time since 1995-96, the Gunners will almost certainly go without European competition.
Arteta's men were eliminated from the Europa League in the semi-finals and approach a midweek match with Chelsea ninth in the Premier League.
Arsenal are 12 points off Chelsea and the top four – Champions League qualification no longer a possibility with three games remaining – and four points shy of seventh, which is set to be enough to reach the Europa Conference League.
They are also four short of last season's points tally, which was their lowest since 1994-95.
Arteta has discussed the need to rebuild in the transfer market, with some members of his team already performing to the extent of their underwhelming potential.
But others have let Arsenal down, the manager suggested.
Asked if his players had given their maximum, Arteta replied: "With the majority of them, yes.
"Some of them can get to a certain level and you cannot push them any further. You want to evolve them but it's not possible.
"When I said a majority, I did not say all of them. Some have a big contribution to make to those results."
Work in the window will be key to changing this, too, according to Arteta.
"Finding a different way to do it, challenging them again, putting somebody next to them to try to push them again," he said, explaining how to get more from his squad.
But there is the possibility Arsenal will have to sell players to make signings.
Last year, they sold Emiliano Martinez to Aston Villa after he had excelled in goal. Villa have kept 14 clean sheets this term to Arsenal's 10, with Martinez preventing 3.8 goals using expected goals on target data – ranking third in the top flight.
This time, Joe Willock – starring on loan at Newcastle United – has been mooted as another £20million departure.
He has five goals since his debut on Tyneside, a tally unsurpassed by Arsenal players in this time and only matched by Pierre-Emerick Aubameyang and Alexandre Lacazette.
Some of the bigger names within Arteta's existing XI might fetch even greater sums, although the Gunners boss is reluctant to make any moves that would weaken his hand.
"Let's see what happens," he said. "It is difficult to predict that one but, in general, we wouldn't like to do that because we are only going to be stronger [if they stay].
"It is clear we want to improve the team. We need some resources."