Uruguayan striker Bueno extended the lead to 3-0 in the 56th minute before last season's Hawke's Bay United Canadian import, Gavin Hoy, pulled one back to 3-1 almost a minute later for the Greeks.
Robertson didn't want to be drawn into any early assertions about their favouritism in the league and was comfortable to go along with the clichéd "we'll take very game as it comes" approach for now as well as reflect on Olympic.
"I don't want to put any sort of labels on us, to be honest, but we have some new players who are still trying to gel but we've got a good and, to use an old cliche, we're taking each game at a time.
"I think they're [Olympic] a good side so they'll be there or thereabouts at the end of the season."
Not a fan of "Tupperware turfs", he was mindful it wasn't easy to come away from the artificial turf with points so to remain undefeated was satisfying.
"I'm not a big fan of artificial pitches because it makes football difficult to play on but, obviously, we have the luxury of the facilities we have at Park Island with a grass pitch."
The Joshua Stevenson-captained Rovers dominated possession in the first half to deny the hosts game time but Robertson felt they had dropped off in the second spell.
He believed that was perhaps because the Greeks opted to tighten up their defence more to deny the Blues more goals.
"It was a long day but a good one for us so it was nice to come away with three points."
The game was played in fine but predictably windy conditions at Wakefield Park which was something the Rovers were prepared for.
Robertson said the blues were heading in the right direction but the campaign was just in its infancy.
Goto has struck twice in as many games, after arriving late in Napier to miss the first round 7-3 victory over promoted Integration Works Waterside Karori.
"He contacted us and wanted to make the most of the opportunity so I looked at the [video] footage and liked what I saw," he said of the technically sound player.
The other Bay campaigners and newbies, Building King Havelock North Wanderers, host Miramar Rangers in a 1pm kick off at Guthrie Park in the village.
It will be a momentous occasion for the win-less Wanderers who are hosting a game of Central League status for the first time in 13 years.
The Blue and Golds were umpteenth-hour call up to enter the league after Team Taranaki withdrew amid claims they were incapable of footing it at the top tier winter league because of a dearth of players and lack of identity in the province,