Rangers have signed Romania central defender Dorin Goian on a three-year deal, subject to a successful work permit application.
The 30-year-old arrives from Palermo for an undisclosed fee.
Clubs had until 2300 BST on Monday to add to their squad ahead of the Champions League third qualifying round ties, with Rangers hosting Malmo.
But Goian is unlikely to feature on Tuesday as it is doubtful a work permit will be granted in time.
The defender was delighted to make the switch from Italy's Serie A and told Rangers' website: "For me, it is a big honour to play for a club such as Rangers with so much history.
"They are one of the top teams in Europe and they have been playing in the Champions League for many years.
"At this moment, I have only good feelings about this move. I do not know a lot about Rangers and I have only really seen them playing on television.
"I don't really know about the players we have, but I know about Mr McCoist because he was a very good player and he is now our manager.
"This is a different challenge for me, but it is a good one.
"I have changed team and the country I am playing in, but I am a fighter and I know everything here is going to be okay for me."
McCoist had targeted the central defence as the main area of his squad requiring extra bodies.
"I think what you see is what you get - he is a strong, aggressive defender who will attack the ball and win his challenges," said the manager.
"In an ideal world, we would have him available for tomorrow's match with Malmo, but the most important thing is getting another player in - especially a defender."
Goian, who has 37 caps, was part of the Steaua Bucharest side that defeated Motherwell in the Europa League in 2009 and scored in a semi-final defeat by Middlesbrough three years earlier.
However, he has had injury problems since joining Palermo in 2009 having initially found himself behind Simon Kjær and Cesare Bovo in the pecking order.
Scotland left-back Lee Wallace was signed by Rangers from Hearts on Thursday following the capture from Almeria of midfielder Juan Manuel Ortiz, while Orebro midfielder Alejandro Bedoya will arrive in January after agreeing a pre-contract.
Despite that, McCoist stressed again that he would continue his search for defenders despite the capture of Goian and the rejection of an offer from Qatar champions Lekwhiya for Madjid Bougherra.
Rangers have been in negotiations with Aston Villa about bringing former Ibrox centre-half Carlos Cuellar back to Glasgow and have made efforts to sign Roland Juhasz from Belgian club Anderlecht.
"The signing of Goian does not mean we will stop there," said McCoist, who had previously pointed out that an injury meant that Cuellar would be unvailable to face Malmo in any case.
"We would still like to bring in another defender. We still have an interest in Carlos and Juhasz."
Juhasz, who is two years younger than Goian, joined Anderlecht from MTK Hungaria in 2005 and was part of the Hungary side defeated 2-1 by England at Wembley in August.