De Boer has made just one signing so far since he was handed the reins at Selhurst Park at the end of June.
Chelsea midfielder Ruben Loftus-Cheek joined the club on Wednesday on a season-long loan, while Ajax's Jairo Riedewald is also expected to join the club.
Palace are set to pay £7.5million for his services, while goalkeeper Jasper Cillessen is being linked with a possible loan move from Barcelona.
However, De Boer is eager to give everyone a chance as the current squad look to improve on last season's 14th-placed finish.
De Boer is currently training his side at St George's Park before they play Maidstone United in their first pre-season friendly on Saturday and he believes the current squad can kick on this season.
"If you want to buy other players, first you have to look in your own kitchen and we have some talented players," De Boer said on the official Crystal Palace website.
"People [at Palace] are very nice, very helpful and really want to make something good out of it.
"Also the players, they are giving 100 per cent in every training [session], it is good to work, so I have nothing to complain about right now.
"It is more about getting the [fitness] load into their body, then next week we will go to more shorter games and the intensity getting higher and higher.
"That is our build-up and in between we are hopefully going to modify our system better and better."
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