Pressure mounts on winless Stubbins
Joel Griffiths put the Jets in to the lead mid-way through the first half before Wellington Phoenix scored three goals in five second-half minutes to ease to a comfortable 3-1 win at Hunter Stadium
Stubbins believes his players could be a 'fear factor' involved with taking a lead with the Jets losing leads against Central Coast, Melbourne Victory, Perth Glory and Melbourne City.
"We are certainly good enough to go and get goals as it's been proven but to get ourselves in a situation where we are questioning ourselves, do we have a fear attached (to being in front)?" Stubbins said.
"Again we have succumbed in a game where we have taken the lead and I think in the first half we controlled the game. In terms of the game plan I thought we were very effective.
"We can keep challenging the group and keep challenging them mentally but you know at some point you have to say are we mentally tough enough and then I have to challenge what we are trying to achieve tactically."
Newcastle had opportunites to extend their lead with Griffiths and Carney both striking the woodwork leading Stubbins to believe that luck has deserted his team.
I don't know how many times we have hit the post and in the last three games, you know it's a little bit ridiculous now," he said.
"I don't want to say luck but we have just had no luck whatsoever to this point."
The Jets injury woes continued ahead of a tough trip to A-League ladder leaders Perth next weekend with Billy Celeski substituted after eight minutes with a groin strain while Marcos Flores withdrew from the squad pre-game with a sore hamstring.