Perez has been a frustrated spectator during the Mariners unbeaten start to the season.

The attacking midfielder suffered a minor hamstring injury in the club's final training session ahead of its 1-0 round one win over the Melbourne Heart and is still to make his A-League debut.

Mariners coach Graham Arnold was hopeful the recruit would be fine to play Adelaide United last week. But the club opted for a safety first approach and left him out.

Arnold will have another look at him at training on Friday before making up his mind and admitted Perez was "very close'' but would not be risked unless fully fit.

"It's been frustrating but we won't be taking any risks with him,'' Arnold said.

With Perez out, Arnold has been using striker Matt Simon in an attacking midfield role. That is expected to continue if Perez is again ruled out.

Simon scored the Mariners goal in last week's 1-1 draw with Adelaide at Gosford.

Despite not taking maximum points against Adelaide, Arnold was happy with his team rallied in the second half.

The Mariners created a host of chances and were unlucky not to net a winner late in the match.

"Things are coming together nicely for us,'' Arnold said. "Sunday will be another tough match."