Murray has revealed that the Ibrox club have waited since the summer to finalise the signing of the German custodian - a deal which was completed on Christmas Eve.
Klos may make his Premier League debut against St Johnstone today after sealing his pounds 700,000 move from Borussia Dortmund. Murray said: "It is the longest transfer I've been involved in during my 10 years at the club. I shook Stefan's hand last summer and we agreed a deal. It was as simple as that. He has shown he is a man of his word and has shown his commitment to Rangers by making a contribution to the transfer fee. He is only 27 yet has a wealth of experience and we are delighted to welcome him to Ibrox."
Rangers' Dutch coach, Dick Advocaat, could drop the current No 1 Antti Niemi to make way for Klos, although Niemi was outstanding in the 3-2 win against Hearts last weekend.
Advocaat said: "We need two or three top keepers at this club. That is very important. But you will have to wait and see if Stefan plays. It is a difficult decision for me to make. However it is a squad game, not just about the 11 players on the field and I want people to be happy. If they are not then, they know what they can do." Rangers' other senior keeper is the injured Frenchman, Lionel Charbonnier.
Celtic, who travel to Dundee tomorrow, will be without Craig Burley. The midfielder was aiming to return after two months out because of a groin problem, only to suffer a breakdown in training. The match may also come too soon for both Jackie McNamara (knee) and Marc Rieper (ankle).
St Mirren have appointed Tom Hendrie as their new manager, after they agreed a compensation deal with Alloa.
Hendrie, who brings his assistant John Coughlin with him from the Second Division club, has signed a two-and-a-half year deal with the Paisley side.
St Mirren turned their attention to Hendrie after admitting they were not in a financial position to make the former Hull City player-manager, Mark Hateley, an offer.
Hendrie will take charge of the First Division club for the first time today against Hamilton. He takes over at Love Street following the departure of the previous manager, Tony Fitzpatrick, earlier this month.Reuse content