The 25-year-old hooker has been sidelined after suffering a broken foot in the second game of the season against the Scarlets in early September.
But after undergoing a rigorous rehabilitation regime, MacArthur has added an impressive four kilos of muscle and is set to hand Glasgow head coach Gregor Townsend a welcome lift by making his return against the Irish.
The Leinster match starts a six- game sequence that will do much to shape Warriors' fortunes for the season ahead, with fixtures against Munster in the PRO12, the Heineken Cup home and away double-header with Castres and the two legs of 1872 cup with Edinburgh.
So MacArthur's return could not be better timed. He said: "It has been really frustrating to have been out for 10 weeks, but the great thing for me, when I look at the fixtures we have coming, is that the biggest games of the season are just ahead and I will be back for them.
"I am on target to be ready for Leinster, with just a few wee checks to be ticked off. I'm really hungry to get back into action.
" The boys have done a fantastic job to set a new club record with the six games unbeaten in the PRO12 and if we can get positive results against Leinster and Munster it would provide a massive boost.
"After that we have the double in the Heineken Cup with Castres and the great thing for us is that the first tie is at Scotstoun on December 7. If we can get the better of them in that one, then it would give us a platform to go to France and we have a very good record over there including wins over Toulouse and Narbonne and a draw at Montpellier last season we should have won. So it is not beyond us to do the double over Castres.
"If we can do that we will be right back in the mix for the Heineken Cup and then the two Edinburgh games finish December. Every one of these games is the type of match you want to be playing in."
While MacArthur has been out, Warriors veteran Dougie Hall has in the main held the No.2 shirt, while young Finlay Gillies has also been using the opportunity to press his claims.
But the former Ayr star believes his rigorous gym work has helped add a new dimension to his game that will help him make an even greater impact from the front row. MacArthur said: "I am not the biggest front row out there and I was determined from day one to be positive and use my rehab as an opportunity to add extra power to my game.
"I have put on four kilos in muscle and, hopefully, that will help give me extra grunt. But I know Dougie Hall and young Finlay Gillies have done well so I am taking nothing for granted."