Lia, who has formed a formidable partnership with Tim Brown in the heart of the Phoenix midfield, was suspended for last weekend's away win at Newcastle after picking up five yellow cards.

"He will be straight into the squad definitely," said coach Ricki Herbert. "He's had an excellent season and he's arguably been the best player in the team so it would be hard to leave him out."

Diego, who had not played since making a late appearance off the bench against Adelaide in round five, filled the role vacated by the Australian and Herbert was pleased with the way the Brazilian responded after weeks on the outer.

"I was very clear to him that he had to step up and he did. I probably didn't intend to leave him on for so long but he was just so clinical with the ball and the possession rate that he had was very high for us so we elected to leave him on," said the Phoenix coach.

"He got through it and he did the role that we asked him to do extremely well."

Whether Diego's efforts are enough to keep him in the starting XI remains to be seen but Herbert felt there was now genuine competition for places.

"I think that sends a message out to them now that we've got a player in Diego who's ready and if they drop their form or whatever he will certainly step in," said Herbert.

The coach does however have one injury concern heading into the match after goalkeeper Mark Paston took a blow to the leg during training on Wednesday.

"I think he's just got a bit of a corked thigh. He just clashed with one of the players," said Herbert. "We'll wait until Sunday but I think he will be okay."

Last week's win was Phoenix's first away victory in more than a year.

"I thought the players were great on the trip and there was just a real air of confidence around the group and everyone was upbeat. It's a strong united team," said Herbert.

"I think the three points last week was a great bonus for us and if we get something out of Brisbane now I'll be delighted."

The 1-0 win in Newcastle was also Phoenix's fifth clean sheet in eight games thanks largely to the formidable duo of Ben Sigmund and Andrew Durante in central defence.

In the same period the Wellington side have won three and lost just once, 3-1 to Sydney FC.

"It's come together nicely at both ends now," Herbert added. "I think the whole group of players have really picked up the responsibility.

"For the (back four) to walk off the park without conceding a goal is important for them because we have got players now that can win games for us.

"There is enough hunger. The players are playing very well at the moment so there's no reason why we can't go and win."