The Wanderers host the Phoenix on Sunday high on confidence from last weekend's 2-1 win over the Central Coast Mariners - the side's first win in five games.

A second consecutive victory in the catch-up fixture at ANZ Stadium would lift the sixth-placed side three points adrift of fourth with a game in hand.

However, a first loss in six meetings with the last-placed Phoenix would leave their finals fate teetering on the edge.

And the playing group have been reminded they can ill-afford to give Wellington a sniff like the one they allowed the Mariners.

A familiar feature of the Wanderers' game this season has been their propensity to drop in intensity after an energetic first 45-60 minutes.

"We spoke with the boys already," Gombau said.

"First half (against the Mariners) was very good and we deserved maybe to score one goal and go into halftime 3-0.

"Second half it's true that mentally and maybe physically we (slowed) a little bit and the Central Coast Mariners became a better team than us.

"It's something we need to improve, something that can't happen again.

"We are working together to ensure that we keep the same performance in the second half as the first half."

Adding to the burden is that the Wanderers face the final eight rounds with only two senior central defenders in Brendan Hamill and Michael Thwaite.

If Robbie Cornthwaite's exit wasn't tough enough, an ACL injury to Jonathan Aspropotamitis has left Gombau severely short staffed.

The coach has already used left-back Jack Clisby as an emergency centre-back and appeared unconcerned about the lack of depth, citing youth team captain Tass Mourdoukoutas as an option.

For Hamill, it's an immediate step up in responsibility.

"It's fallen into place to be that way with Corny leaving and Aspro getting injured but we've got a lot of depth in the squad," Hamill said.

"Me and Thwaitey have played the past few games together and our relationship is growing and we're getting more confident and stronger with each performance."

STATS THAT MATTER:

* The Wanderers are undefeated in their past five games against the Phoenix (W3, D2) but have won only one of their past six home fixtures

* Wellington have scored 10 headed goals this season, three more than any other team and seven more than the Wanderers (3)

* Brendon Santalab has scored eight goals in his past five games against Wellington, including three braces.

Australian Associated Press