Hamer, the man who put a huge dent in Scotland`s unsuccessful World Cup campaign last year by sending off Gary Caldwell in Oslo, came to the SFA's rescue after their own category one referees withdrew their labour.

The experienced Hamer will take charge of Celtic`s Clydesdale Bank Premier League clash against Inverness on Saturday before he and his two assistants from Luxembourg cover Rangers' trip to Dundee United on Sunday.

A U-turn by Polish authorities, who withdrew an offer to supply three referees, means Hamer has been handed two matches, and the SFA gave him the biggest ones.

Hamer is well known to Scottish football fans following his performance in Scotland`s 4-0 defeat to Norway in August last year.

The Scots were level in the crunch World Cup qualifier until the 34th minute when Hamer booked then Celtic defender Caldwell for the second time in two minutes.

Scotland captain Darren Fletcher was among those who criticised Hamer, saying: "That's so hard to take because you expect top referees to be in charge of games as important as this one. There's a World Cup at stake.

"I don't know how many big games he has to take care of every season in Luxembourg."

However, before leaving Oslo, Hamer told Press Association Sport: "People often criticise me because I come from Luxembourg.

"I might come from Luxembourg but they should know that I referee mostly in the top leagues in France and Belgium."

"I refereed the game between the same two sides four years ago in Oslo when Scotland won 2-1. Funnily enough there was no criticism of me after that game."

Rangers striker Kenny Miller described Caldwell's dismissal as a "horrendous decision," while then Scotland boss George Burley questioned Hamer's use of his yellow cards.

Hamer, 44, has been taking charge of Champions League matches for 10 seasons, the latest on Wednesday when Hapoel Tel Aviv beat Benfica 3-0.

He has refereed two Rangers games, a 2-0 UEFA Cup win over Werder Bremen in March 2008 and a 1-1 draw against Villarreal in Spain two years earlier.