"I'm still recovering [from an injury] but I'm fit to go. However, the boys are doing well so I'm not going to dislodge players when everything is going well."
The mid-table hosts struck first on Saturday, Josh Smith drawing first blood in just the sixth minute.
That stung the visitors into action with Saul Halpin equalising in the 16th minute and Ryan Tinsley making it 2-1 in the 21st.
Centre-mid Tom Biss joined the party in the 43rd before Josh Stevenson chimed in with two - in the 53rd and 73rd minutes.
Centreback Finlay Milne put his hometown team out of their misery with a goal following a cornerkick scramble in the 83rd minute before Smith pulled one back four minutes later for the 6-2 result.
Marist coach Simon Lees said his troops were making too many silly mistakes across the park.
"You can't give those players [Blues] those sorts of opportunities.
"We have a bloody good squad," Lees said, saluting reserve goalkeeper Heath Butler in his league debut after regular Gurkarnvir Singh "was crook as a dog".
He said Marist would come out better on the ladder after collecting six points from their last three games.
The Rovers host Petone FC this Sunday at Park Island before rolling out the carpet for Stop Out in the Chatham Cup playoffs the following Sunday.
"A lot of teams are close to each other so there are no easy games," Robertson said.
English import Halpin, who hobbled off early on Saturday, is the only niggly but Robertson said he should be fine.
