The former Fiorentina player has not been the only frustrated spectator since his pounds 4m arrival last summer. Poor defending has done as much as anything to undermine the champions' hopes of claiming their 10th consecutive Scottish title.
However, after months of injury agony from an Achilles problem picked up in a pre-season friendly, Amoruso made a mightily impressive competitive entrance in a Rangers shirt a week ago.
Coming off the bench just 20 minutes into the 2-1 Scottish Cup semi-final win over Celtic, the Italian was calmness personified as Walter Smith's team weathered the early storm to claim a final date against Heart of Midlothian on 16 May.
"I was more worried about putting Lorenzo in last week, but the way he played, he will start the game this week," Smith said. "It was difficult for him and he would admit that himself, but he came through it OK.
"We were under a bit of pressure when he came on but he coped with that well enough. I would hope he would continue to do that this week and other weeks."
Amoruso looks likely to be a straight swap for the man he replaced, hamstring victim Gordon Petric, in what could otherwise be an unchanged Rangers line-up. Smith revealed that the German midfielder, Jorg Albertz, has not trained all week with a foot injury that has prevented him kicking a ball, but that the player himself is keen to play.
The champions are chasing a sixth successive win in league and cup since going down 2-1 at Motherwell on 14 March.
"Three weeks ago our aim was to win all the games that we had left and we have managed to do that so far," Smith said. "We have had to get results from being under that type of pressure and Sunday's match is no different. The pressure is on us to go out and win the game."
A victory by more than one goal would see Rangers take over the leadership from Celtic with four games remaining, but Smith does not believe the three-point differential will have a great bearing on the game.
"It places Celtic in a position where they don't need to win as much as we do," he said. "A draw is obviously a result for them, but I don't think they are the type of team that goes out playing for draws."
Smith would not be drawn on whether a victory for the green and white half of Glasgow - allowing the Parkhead side to draw six points clear - would be an insurmountable obstacle.
"I don't consider that aspect of it at this stage," he said. "Our whole focus has to be on winning the match."
Celtic could be without five players in addition to Stephane Mahe, who is already out for the season. Alan Stubbs and Jackie McNamara missed Wednesday's 2-1 win at Kilmarnock, so need late fitness checks, and three injuries collected at Rugby Park - Enrico Annoni (foot), Morten Wieghorst (calf) and Tom Boyd (hamstring) - are also a concern for the coach, Wim Jansen.
Winger Kevin Harper will return for Hibernian after a thigh injury and is expected to start the most important Edinburgh derby for some years at home to third-placed Hearts today. Alex McLeish's options have widened with the return of striker Barry Lavety and central defender John Hughes from suspension, but Shaun Dennis is missing with a knee problem.
Hearts have doubts over midfielder Colin Cameron, who missed Wednesday's 1-1 draw with Motherwell with a pelvic problem, and Paul Ritchie, who dropped out of the same fixture because of a virus. Steve Fulton has resumed light training and should play.
Scotland's lower league clubs have decided to stay with three divisions of 10 teams next season. The decision, taken yesterday in Glasgow by representatives of the clubs on the Scottish League Management Committee, ends uncertainty about the League's structure.Reuse content