The Blues defender is hoping to rehabilitate his career in Greece after being stuck with the academy players in west London
The 26-year-old arrived at Chelsea in 2015 from Augsburg for an initial fee of £14 million ($19m), rising to £22m ($30m) with performance-related add-ons, but has found his chances limited.
Rahman is understood to be fully fit having proved his fitness playing with Chelsea’s Under-23s in a series of games, including three Premier League 2 matches.
His impending move follows Danny Drinkwater’s loan switch to Kasimpasa in the Turkish Super Lig, with the pair having been stranded after failing to find loan moves in the summer transfer window.
Watford and Middlesbrough were both interested in Rahman in the summer, while there were two other clubs – one in Spain and one in Germany – who were considered by Rahman before he chose Greek outfit PAOK.
Back at Cobham Training Centre, Chelsea are beginning to reduce the size of their loan group ahead of FIFA’s new regulations to limit big clubs hoarding talent.
The over-23 non-academy trained players are particularly affected and Chelsea have already allowed long-time loanee Lucas Piazon to leave permanently to Braga on a free transfer.
Rahman will likely be among those instructed to find a permanent move in the summer but the left-back’s focus is on proving his fitness to prospective buyers.
Before he was sacked by Chelsea on Monday, Frank Lampard left the door open on sending Billy Gilmour out on loan even after a masterful midfield display in the 3-1 FA Cup win over Luton.
Kepa Arrizabalaga and Marcos Alonso were also among those who could have left in the January transfer window but their high salaries are putting off possible loan clubs.
Chelsea were looking to send out players from the academy but there hadn’t been much movement ahead of Thomas Tuchel being appointed in Lampard’s place.