"We managed to work through a couple of things so I'm delighted to be a part of it," he said, saluting Waitakere United coach Chris Milicich for recognising his individual capacity to help Team Wellington's cause once more.
Robertson, who also has renewed a two-year contract with the Napier City Rovers club over the winter season to help the province's flagship Thirsty Whale-sponsored side during the Central League campaign, has competed in three O-League finals with Team Wellington but lost every time to Auckland FC.
Wellington did win the O-League last year but Robertson didn't play for them, after pledging his allegiance to the Bay United franchise where he was appointed 2017-18 captain but sacked this summer.
The Brett Angell-coached Bay United, akin to Waitakere United, are out of the running for the Premiership playoffs but will resume their campaign tomorrow because of the O-League commitments of Wellington and Auckland. They play Waitakere United in a televised 4.30pm kick off match at Trusts Arena, West Auckland.
Robertson said it was nice to put aside the rebuff and to have undergone rehabilitation to his injured arm to return to the higher echelons of the O-League.
"It's good be back in a professional environment so it's going to be a good challenge for me personally."
He said it also was timely to return as player/coach of the Blues considering what they had tried to achieve at the Park Island club for the past few years.
"That success led to a title in the league last year so we want to try to build on that and face the challenge of trying to retain it.
"It just continues the good work that's been done there so I'm really happy in there after we've made a lot of progress over the last few years with professionalism both on and off the field so it's important that we just continue to do that."