The Mariners conceded the only goal in the match midway through the first half when Jets striker Jeremy Brockie pounced on an errant back pass out of defence by Bradley Porter to slot home a well-taken opportunity.

The Mariners attacked strongly in the second half and went close to grabbing an equaliser but were unable to convert their chances.

"I think we beat ourselves today," Arnold said after the match. "Maybe it was down to the heat but the first half both sides were a bit flat and a couple of our mistakes ended up costing us.

"But I was very happy with our performance in the second half, we create enough chances in the second half to win it, it was a very open game on the second half."

"Matt (Ryan) had to make a couple of saves, but at the same time we had enough chances to at least get an equaliser."

Arnold said the reason for the slow start from last season's Grand Finalists was a lack of confidence after losses to Brisbane Roar and Newcastle Jets as well as an underwhelming performance against the Gold Coast United that saw the Mariners snatch a lucky late equaliser.

"I think their confidence might be down at the moment but it is just a process we are going through," Arnold said of his players.

"You make your own luck and that starts with a lot of hard work on the training field.

"The boys are disappointed today to lose but I saw a lot of positives out there compared to last week's performance against the Gold Coast and a lot of that was down to the hard work we did on the training field during this week and we have arrest day tomorrow then we will start again.

"I think the competition will settle down a bit after six or seven weeks, it is all over the place at the moment but it was a much improved performance compared to the Gold Coast game.

"When I say confidence I probably mean we took a bit of a knock especially after last week's performance.

"We started a bit flat today and after we conceded a goal the confidence took a bit of a knock there but in the second half we showed what we can do and how we can play. So confidence is probably not the right word – we just took a bit of a knock.

"It is only three games and the most important thing is the process. The big picture is the season, so we just get back on the training field, work hard and go again."

Arnold also admitted that the absence of injured skipper Alex Wilkinson was having an adverse effect on the Mariners performance.

"What we do miss with WIlko (Wilkinson) is his leadership," said Arnold.

"He has been captain of the club since day one and he has a lot of respect within the team for what he has done and who he is and we miss his leadership.

"When things are down on the field he brings in the positive talking and he groups everyone around him as well and if we are missing anything that is it."