THERE were moments when Jets defender Antun Kovacic wondered whether it was all worth it.Ostracised by coach Gary van Egmond, Kovacic was banished to another part of the training ground to work on his own.He would do shuttle runs while the rest of the squad worked on shape.It was the ultimate wipe. Demoralising.Many would have given up.But not once did Kovacic's commitment or work ethic waiver.Every session he would finish dripping with sweat.Sometimes he stayed on to do extras.Life can be tough when you fall out of favour with a coach.But whenever Kovacic was at the end of his tether, he recalled his other life working as a machinist in the family business in Melbourne.Rising early to be on the tools by 7am. Days spent in a factory building moulds for plastic bottles and lids. Freezing in the winter. Boiling in summer. Knock-off time was when the job was done.Don't be misled: Kovacic is proud of his roots and has little doubt that he will return to the family business one day just not yet.Newcastle is the 27-year-old's second A-League club.He had a taste of full-time football during a six-week stint at Melbourne Victory as an injury replacement two years ago."Coming up here was like a dream come true again," Kovacic said."I said to myself, 'I am not going to let it go.' "On Sunday, Kovacic's persistence and unrelenting determination finally paid off.The tall centre-back scored his first A-League goal, crashing home a header from a Kaz Patafta corner to set the Jets on course for a moral-boosting 2-1 victory over Perth Glory."I had missed a header moments earlier," Kovacic recalled."Coming up for the corner I said to myself, 'Come on, I have to get on the end of this.' "His reaction was pure ecstacy.All the hardship, frustration and self doubt was swept away in a frenzied albeit unconventional goal celebration."I was on the floor and had [Jets midfielder] Matty Thompson standing above me," Kovacic said."He told me to get up and run, and I did. I was stoked."Some of the boys said it was the quickest 10 metres I have run all year."The Perth win was the second straight start for Kovacic.Initially promoted out of necessity, the place is now his to lose.After virtually writing Kovacic off, van Egmond was more than happy to eat humble pie."I admit I have ridden him pretty hard," the coach said."It is always a good thing when you see players go through a hard time and come out the other side."He is very popular among the boys. You could see the response when he scored. Everyone was extremely happy for him because he has gone through a hard time."On the goal, the coach was just as complimentary."He did exactly what he was asked," van Egmond said."He started his run from outside the box and timed it coming in. He was disciplined and concentrating on where he had to be at the particular time."Looking to add depth to paper-thin defensive stocks, van Egmond signed Kovacic to a two-year deal from Victoria Premier League club Richmond in July.Despite having played 59 games for the Melbourne Knights in the old national league, he struggled to make an impact and quickly dropped down the pecking order."He was not doing what we wanted him to early in the season," van Egmond said."He was finding it very difficult, especially in training games."Sometimes it takes a while for them, especially going from two to three nights a week in the state league to full-time professionalism where you need to back up day after day, sometimes with double sessions."Sometimes it takes time to acclimatise."Kovacic's cause was not helped by an alcohol-fuelled incident in December in which he allegedly urinated in a Brisbane motel room. He had earlier played youth league as an over-age player and conceded an own-goal in the dying stages for the Jets to lose 3-2.He received a sanction from the club for his actions, and his behaviour since has been exemplary."I tried to stay as positive as possible," Kovacic said."My confidence was down and that showed on the training track as well. "I had to stay positive. I had great support from the boys and that pulled me through."Despite his recent rise, Kovacic understands more than most that things can change very quickly.Adam Griffiths returns from suspension for the final A-League game against Sydney FC at the SFS on Sunday.The Jets also hope to have Socceroos defender Nikolai Topor-Stanley on deck in time for the Asian Champions League, which kicks off on March 10 away to Beijing Guoan."From the very start I knew it was always going to be hard for me to get into the side," he said."When the opportunity arose I had to take it with both hands, and I don't want to let it go now."