Goalkeeper Jacob Spoonley returns after injury to further bolster the squad still without Ian Hogg and Emiliano Tade.
Coach Ramon Tribulietx is happy with the acquisition of Spanish midfielder Ruiz, who had his first taste of domestic football in last week's ASB Premiership win over Hawkes Bay United.
"He's very good at playing that last ball and, when you look at our style, that is probably one thing we miss sometimes," said Tribulietx.
Waitakere coach Neil Emblen will give his players a light run this morning before flying to Fiji.
While Waitakere have stuttered on away trips in both competitions this season, Emblen is confident they can turn it around. He takes heart from last Sunday's ASB Premiership win over Team Wellington.
"A few of the boys have been a bit fatigued at training this week," said Emblen.
"That has come from the extra effort I asked for and got against Team Wellington. I don't mind if they are tired at all trainings so long as they have put in an effort like that."
Emblen loses midfielder Martin Bullock to suspension but happily welcomes back Aaron Scott after he played from the bench last Sunday.
In other action today, two matches in the White Ribbon Cup - for teams not involved in the O-League - will be played.