McCarthy added Brighton & Hove Albion striker Aaron Connolly and Blackburn Rovers defender Derrick Williams to his squad on Saturday evening after the withdrawal of the injured Ronan Curtis, Darragh Lenihan and Greg Cunningham.
Connolly and Williams both joined up with the senior squad at their hotel on Sunday evening and will train at the FAI National Training Centre at Abbotstown on Monday afternoon.
With 24 players now in camp for the double header away to Georgia and Switzerland, McCarthy won’t make any final decision on the travelling party until he gets medical updates on Duffy and McGoldrick.
“Our medical team are in constant touch with the two clubs and monitoring the treatment programmes and progress for both Shane (Duffy) and David (McGoldrick),” McCarthy told FAI.ie
“We will give both of them as much time as we can before making that decision. Both Brighton and Sheffield United are doing everything they can to get them fit for us and I would like to thank them for their co-operation.
“Aaron Connolly and Derrick Williams are in camp now and I will see how Shane and David are doing before finalizing the travelling party for Thursday’s flight.”
McCarthy’s players were amongst the goals again at the weekend as they prepare for the Group D clashes away to Georgia and Switzerland with Ireland sitting on top of the table with 11 points from five games.
Connolly marked his full debut for Brighton with two goals in a 3-0 win over Tottenham Hotspur, while Jeff Hendrick was on target as Burnley won 1-0 at home to an Everton side who had captain Seamus Coleman sent off.
Conor Hourihane’s goalscoring form continued in Aston Villa’s 5-1 victory at Norwich City and Scott Hogan came off the bench to get the winner for Stoke City as they beat hosts Swansea 2-1.
“Goals breed confidence so there will be a pep in their steps when our players train together on Monday afternoon,” added McCarthy.
“The first bonus this weekend was to see so many of our players start for their clubs and the second bonus was the fact that some of them scored as well. Aaron (Connolly) grabbed the headlines with those two goals for Brighton and he is now in the squad.
“I’ve said all along that any young player who is getting first team football and playing well would be a real contender for the squad for these games. Aaron has got into the Brighton team, played well and scored so he deserves this chance.
“Jeff (Hendrick), Conor (Hourihane) and Scott (Hogan) were on the scoresheet as well on Saturday so they will be buzzing looking ahead to Georgia and Switzerland.”