Rangers are set to make their second signing of what looks certain to be a packed summer of deals with striker Antonio Colak on the verge of a move - but indecision at PAOK is holding up the deal.

Razvan Lucescu's side were open to negotiations but, since agreement was reached haven't been forthcoming in making a final decision on the 28-year-old's future. There has been speculation they are not keen on signing off on the move without a replacement secured. Some reports have emerged from Greece that a third Rangers offer is being deliberated on but that's not the case, with particulars between the clubs and player now finalised. 

Transfer dealings are complex and multi-faceted at the best of times but power brokers at Ibrox are feeling frustrated by the bizarre hold-up of the deal. Terms have been agreed on a contract that essentially sees a like-for-like swap with misfiring Cedric Itten in financial terms after the striker made a £1.5m return to Switzerland earlier in the window.

Colak has essentially packed his bags to come to Rangrers and is keen to move to Scotland having been wowed by the Ibrox atmosphere when turning out for Malmo. He sees the transfer as a positive step for his career and has requested it be finalised as soon as possible.

The Rangers Review understands that a deal of around £1.8m has been agreed with the Greek side. This represents a substantial outlay for a player who, given his age, arrives as a finished article signing rather than a project player who can be sold at a profit down the line.

A three-times capped Croatia international, Colak comes off a poor Super League 1 season in Greece for second-placed PAOK. His goal return of three in 23 appearances looks paltry but dig a bit deeper and the potential value becomes apparent. While there can be no sugar-coating the goal numbers from his time in Salonika, his record in other leagues has been excellent in recent years.  

READ MORE: Antonio Colak Rangers transfer scouting: The Champions League nemesis with ice in his veins

Rangers know only too well about his scoring prowess in Sweden where his double helped Malmo to the riches of the Champions League at Rangers' expense. He blasted 19 in 40 during a successful loan season many were surprised wasn't extended permanently. Look back further and the form that got him to Greece in the first place was excellent. He scored at a better rate than a goal every second game at Riejka in Croatia, a league where Rangers have previously have a decent hit rate with Borna Barisic and Niko Katic.

A tall, physical striker - scouting suggests he's mobile and willing to push onto the last line of defence meaning the Ibrox club are unlikely to become one-dimensional if he comes into the side.

He's also clearly a player who grafts for the cause as PAOK boss Razvan Lucescu explains: "Antonio gives 150 per cent to training and to games. It makes no difference to him whether he starts or comes on as a sub, his work rate is the same. He is one of the most hard-working players I have ever been involved with. I have only good things to say about him.

"It doesn't matter what league Antonio plays in, he would score goals anywhere he plays. When he returned to us after his loan spell in Sweden, you would have perhaps expected his confidence to have dropped slightly because he had problems here when he first signed. But he quickly showed that wasn't true and is a hugely important player for us.

"He's quick, smart and good with the ball at his feet. There are so many ways he can break up a defence. In Greek football, we play against teams that do not give much space and you have to create it and he is excellent at doing that. He is a player who has my complete trust."