It took Miramar about 60 minutes to equalise.
Had Wairarapa beaten Miramar, they would have done the Blues a favour as the Rangers are sitting comfortably with a six-point buffer and a game in hand.
"We have to beat them [Miramar] and hope they lose some points, too."
Both the Rovers and Miramar are in the fourth round of the Chatham Cup (national knockout) this weekend.
The Blues play Tawa at the grass Redwood Park this Sunday in the 2pm Cup match.
Upper Hutt player/coach Pedro Garcias had informed them the ground "wasn't that good apparently" so Robertson won't be surprised if it's moved to an artificial surface.
"We prefer grass because it suits our style of play where we get the ball down to pass so the astroturf can be better than a boggy pitch."
The Rovers beat Tawa 3-1 in the first round of the league on April 27 but while unbeaten at Bluewater Stadium, Park Island, don't have a raving review on the road.
"We're expecting a tough game from them because it's their club day.
"If we apply ourselves to meet the high standards we set then we're confident we'll win the game," he said, although he was mindful the Cup "raises standards with the media hype".
"The league positions don't mean a great deal when you're talking cup football," Robertson said of Tawa who are third from bottom in the league and lost 5-1 to Petone on Saturday.
And what of Saturday's game?
The Rovers controlled the first half but didn't make most of their chances with a 1-0 lead into halftime from an Andy Bevin goal in the 25th minute.
The visitors were stung into action when left winger Steven Thomas equalised, 1-1, in the 51st minute as the hosts' got their tails up.
"I told the boys the game was far from over," Robertson said.
Striker Sam Messam responded in the 71st minute.
Josh Stevenson made it 3-1 in the 83rd and teenager Angus Kilkolly put Upper Hutt out of their misery six minutes later.
Kilkolly now has six goals in the golden boot race.
In the other game on Saturday, Western Suburbs drew 2-2 with Lower Hutt City.
