The 23-year old Latvian left-back is on the verge of penning a deal which will see him spend the rest of the season with Killie after finding game time in England hard to come by.
"He should be in tomorrow (Friday) all going well," Johnston said on Thursday.
"He can play centre-half or left-back. He's a Latvian international and he is at the right age as well."
Maksimenko joined the Seagulls from Skonto Riga 12 months ago before spending a month on loan with Yeovil Town in March last year.
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