Amoruso was marking Dortmund`s Nigerian striker Victor Ikpeba and it is alleged that television pictures show the Italian hurling racist abuse at Ikpeba.
The two clashed repeatedly throughout the match although Rangers have insisted that they will deal with the incident internally after a lip-reading expert said there was "no doubt" that Amoruso had abused Ikpeba.
Rangers spokesman, Martin Bain said:"Any allegations made against the football playing staff will be considered and if necessary dealt with internally by the manager, which is standard practice."
Amoruso was part of the Show Racism the Red Card Campaign earlier in the season but he admitted he called the Nigerian `some names` during their half-time bust-up after Ikpeba had pushed him.
Amourso was quoted in the Daily Record as saying:"Yes, I had an arguement with Ikpeba. He called me some names and I called him some names, but these things happen when you are playing important games."
But Ged Grebby of the same campaign said: "Amoruso has to apologise to Dortmund immediately. Rangers should make sure he`s hit in the pocket and attends a re-education course about racism."
Meanwhile furious Gers boss Dick Advocaat has slammed his players and admitted they are not good enough. He said:"This is a very painful defeat to take. But this game just shows what we already knew, that some of my players don`t have the quality to play at the highest level.
"You need to defend in the last minutes of a game with 11 in the box and just kick the ball away but we had players who wanted to try to score a goal.
"To lose a goal in 92 minutes says it all."
Nic Evans
