Ross confirmed after the game the injections McGeady had been taking did not work to their usual affect, forcing him withdraw from the matchday squad all-together.
However, Ross refused to rule McGeady out for the showdown at Fratton Park, although admits his situation hasnt changed.
“Hes not any different he was prior to the first-leg,” Ross said in his pre-match press conference.
I felt I was ready to start, of course – I finished the game at Southend and Ive felt since I came back that Ive worked hard to get back to where I am but thats the managers decision and I respect that,” Maguire said.
Sunderland will have Alim Ozturk available for selection after his red card was overturned on Monday afternoon.
Despite playing the final 20 minutes with 10-men, Ross believes its hard to judge whether it affected the final result.
Ross instead gave Lynden Gooch a chance to impress but Maguire announced his second-half arrival in spectacular fashion, scoring a fine volley to give Sunderland the crucial lead ahead of the second leg.
Michael Doyle: Portsmouth generated one of best atmospheres of my career – and those fans will help defeat Sunderland
Ross said: “I did think it was the incorrect decision so Im pleased that common sense has prevailed.
Doyle said: Some players will thrive in that Fratton Park environment. You would certainly expect Sunderland to turn up and embrace it considering some of their team have played in the Premier League.
“It obviously disappointing as it does have an impact on the game but we cant do anything about it now.
He said: “I dont want to dwell on it too much, itd be wrong to say that because you have 11 men on the park, youd score again.
There was a lot to be learnt from that, we probably got too caught up after scoring and suddenly Plymouth were in the lead. You have to control yourself when you are in that situation.
“You dont know the rest of the game would pan out. Im just glad we have him available for the second-leg.”
Jack Ross has provided a fitness update over attacking duo Aiden McGeady and Duncan Watmore ahead of Thursdays Sky Bet League One Play-off second leg at Portsmouth.
McGeady was forced to withdraw from the first leg warm-up on Saturday after hed initially been named in the starting XI to face Portsmouth.
Watmore, meanwhile, is back in training and close to full fitness after enduring a spell on the sidelines with an ankle ligaments injury picked up at Wycombe Wanderers in March.
Speaking at Tuesdays press conference, Ross provided the latest on the pair as Sunderland look to make the most of their first leg advantage and seal their place in the final at Wembley.
He continued: Duncan has trained well and with that in mind hes probably put himself into my thoughts for Thursday.