Shane Duffy sends this message after emotional week for Brighton, Celtic and Ireland

The 28-year-old defender, who completed a loan move from Brighton to Celtic earlier this week, was at fault as the Bulgarians took a 56th-minute lead through Bozhidar Kraev at the Vasil Levski Stadium in Sofia on Thursday evening.

However, he atoned for his earlier error with a headed equaliser from substitute Brady’s corner in the third minute of stoppage time – his fourth international goal – to ensure Stephen Kenny’s first game as manager ended 1-1.

Asked about his late intervention, Duffy said with a smile: “It was nice to get it, but I’d rather have played better, to be honest.

“I fancy myself every game, if the delivery is right. I had a few chances. I knew when Robbie came on I was going to get a chance from him. He’s got a wand of a left foot.

“He knows where I like it. He stuck it on my head and put it in.”

There were positives and negatives in Bulgaria as Kenny’s new-look team – 19-year-old Norwich striker Adam Idah was asked to spearhead a youthful three-man frontline on his senior international debut – attempted to implement the new manager’s philosophy after only a few days together on the training pitch.

Idah was flanked by Albion's Aaron Connolly, 20, and Callum O'Dowda, 25.

Ireland are yet to win a Nations League game after five attempts now, but they will get another chance when Finland, who lost 1-0 at home to Wales, head for Dublin on Sunday.

Reflecting on an a match in which he earned his first competitive start since June 30, Duffy said: “We haven’t had many games and we were straight into an international game, so it was tough on some of the lads. Personally, I haven’t played in a long time, so it was tough.

“We have got to keep going, recover and try to get the three points on Sunday.”