Rangers are confident there is no substance to Maribor's complaint that Carlos Bocanegra was ineligible for last week's Europa League tie in Slovenia.

The Ibrox club have released a statement claiming to be "surprised" by Maribor's protest about the American's debut.

It is unclear whether Uefa will even investigate because Maribor may not have registered their complaint in time.

Article 23 of Uefa's competition rules states that protests must reach their Control and Disciplinary Body in writing, with all details outlined, within 24 hours of the match in question.

A Uefa spokesman said: "The first step is now to determine if the protest has been sent in line with the regulations.

"If it had all been done properly, the CDB would consider opening disciplinary proceedings.

"It is therefore very hypothetical to mention any possible sanction for the time being."

Bocanegra was unable to play against Motherwell on Sunday despite having made his debut three days earlier in Slovenia.

At that point he met Uefa's rules to play in the Europa League but not the British government's to work on UK soil because he had yet to be granted a UK work permit.

Rangers were in regular contact with the SFA while processing Bocanegra's paperwork and are relaxed about the matter because they requested, and were granted, clearance so they had a valid registration and contract.

Rangers' belief is not having a UK work permit at that point was irrelevant because, as far as Uefa were concerned, he registered to play home or away. He now has a permit, too, and will make his Ibrox debut tomorrow night.

Uefa charges around £870 to receive protests and Maribor paid that, seemingly in the hope they might be awarded a 3-0 scoreline from the first leg or even have Rangers expelled before the second leg.

"We are extremely surprised by the complaint of NK Maribor," said a Rangers statement. "As confirmed by the SFA, Carlos Bocanegra was deemed eligible to play at a domestic level within the Uefa deadline in accordance with the requirements of the Uefa regulations. We are confident that the complaint of NK Maribor will be rejected by Uefa."

Earlier Maribor spokesman Zeljko Latin was quoted saying: "How can the player have the right to play in the European competition on the Thursday night, but didn't have clearance to play in a domestic match in Scotland three days later?"

"We are now awaiting a decision from Uefa. It's hard to say when they will make that decision. We are mentally preparing for the match as if it is 2-1."

Rangers could be fined, warned or even thrown out of the Europa League if the complaint was investigated and upheld, but they are confident this won't be the case.

lTickets are available for tomorrow night's return leg of the Europa League play off with Maribor, kick-off 7.30pm. £25 adults, £15 concessions and £5 kids from 0871 702 1972, rangers.co.uk and the ticket centre.