Crusaders head coach Scott Robertson is off-contract with the franchise at the end of 2019.

Scott Robertson will observe All Blacks coach Steve Hansen's looming decision surrounding his future with an eager eye.

Off-contract with the Crusaders after the 2019 Super Rugby season, Robertson makes no secret Hansen's decision will play a part in his own "big decision" in three or four months.

Hansen, 59, will shortly decide whether or not he wants to coach the All Blacks beyond next year's World Cup in Japan. If he indicates he does, it would then be up to the NZ Rugby board to decide if they want to re-appoint him.

Robertson, having guided the Crusaders to back-to-back Super titles, and New Zealand to an under-20 World Cup crown in 2015, is one of a bunch of possible candidates, should the job become vacant.

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PHOTOSPORT Steve Hansen is expected to announce whether or not he wants to continue coaching the All Blacks before the end of the year.

"The All Blacks job doesn't come up too often. When it does, you have to have a real good look at it," Robertson said on Tuesday.

"The biggest thing for me, that's served me well, is the patience side of it, and the ability to get your timing right. I've got a great job at the moment and I've got a big decision in the next three or four months - what's going to happen in 2020, and I'll just see where the cards fall with other coaches and just see what opportunities there are."

One card has already fallen in the aftermath of the 2018 season.

Ireland's Kiwi coach, Joe Schmidt, announced he will finish coaching after the 2019 World Cup, leaving defence coach Andy Farrell to take over.

Schmidt, having guided Ireland to a 16-9 win against the All Blacks less than a fortnight ago in Dublin, had been widely touted to return home and succeed Hansen.

GETTY IMAGES Crusaders coach Scott Robertson, right, and assistant coach Jason Ryan chat to captain Sam Whitelock at a training session earlier this year.

Robertson is good friends with Ireland assistant coach Greg Feek, a former Crusaders teammate, and suspects Schmidt will take one or two years to recharge the batteries.

GETTY IMAGES Crusaders head coach Scott Robertson, centre, guided the Christchurch-based franchise to a second straight Super Rugby title in August.

Asked whether he was interested in other jobs in addition to the All Blacks, Robertson said he was going into the next three or four months with an open mind, although Hansen's decision would play a "big part" in his next move.

"You look at everything, every time this comes up," Robertson said. "When you are a coach, you have to look at all options and that's what I'm doing at the moment. My foremost is here at the Crusaders. We've got great continuity, cohesion, I love the boys.

"I'm working with the New Zealand Rugby union at the moment about what it [2020 and beyond] looks like. We know Steve [Hansen] is going to make a play soon, so we'll see what he has to say."

Robertson's timeline to decide his future means the Crusaders will head into the 2019 season unsure if the coach who has done wonders since taking over from Todd Blackadder ahead of the 2017 season will be back.

Should the 44-year-old decide to extend his tenure beyond three years at the Christchurch-based franchise, you can guarantee the Crusaders board will waste no time placing a contract under his nose.

"I'm fortunate enough to be in a place I've played for a long time and my family is settled here. It's actually quite a nice time to be making a decision," Robertson said.

"I think of my playing career and coaching career to date, you look at your circumstances. They're favourable for me at the moment and patience has served me well to date. Now, for me, it's a big decision in the next year."