Self-confessed 'egoist' Giorgos Giakoumakis admitted he was left frustrated by his start in the MLS after red tape delayed the ex-Celtic star's debut.
And he believes it contributed to him drawing a blank on his Atlanta United bow.
Giakoumakis eventually received his work permit after a delay of several weeks and came on for the final 31 minutes of his side's 1-1 draw against Toronto and saw a goal disallowed for offside.
But the Greek international admitted he wasn't at his best because of the hassle of getting hold of the documentation that saw him have to Canada to go through the paperwork before making his bow in the USA.
Giakoumakis said: "I was frustrated with the length of time it took to go through the visa process.
"The travel and the visa issues tired me out. I felt tired although it wasn't a fitness thing.
“I demand a lot of myself. Even if I score a hat trick sometimes I will not be happy. Sometimes I’m too egoist. I know it’s not good, but this is me.
"Hopefully, I will be hit top form in a couple of weeks or so.
"I wanted to thank the fans for the welcome they gave me."
Meanwhile, Celtic manager Ange Postecoglou enjoyed watching his players reap the rewards of their hard work through their Viaplay Cup celebrations – in the knowledge they would be even more motivated for league action.
The cinch Premiership leaders secured the first silverware of the season by beating Rangers at Hampden last weekend.
And Postecoglou feels the experience has sharpened the competition for places ahead of Sunday’s clash with St Mirren.
“I enjoyed Sunday, I enjoyed the day, I enjoyed our performance, I enjoyed the aftermath,” he said.
“I said after the game that there is a relief because you carry that weight of responsibility for everyone involved and you want the right outcome.
“But after that I enjoyed the night. It was a quiet night for me but I enjoyed it, I enjoyed watching other people enjoy it, whether that was our supporters, or people who are involved with the football club.
“We had Monday off which allowed me some family time and reflection, which was great.
“I think most of the lads enjoyed having a bit of a break from everything and we were back in the building Tuesday and preparing for Sunday’s game so it’s been a normal week apart from that.”
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