"As time goes on, I will realise just how different things will be. When it comes to the games, it will be harder to watch," he said.
"But the main thing is that it will give me more time at home, and also with the Sale squad, because last year during the international period I think we lost six out of seven games.
"I've made a decision based on some very important things, mainly family. It's time for other people to come through now."
New Zealand-born Van Gisbergen, who qualifies for England on residency, is set for a November Test debut against Australia at Twickenham and Robinson believes the 28-year-old is the leading contender to take over his position.
"He has been playing very well. His all-round game is very good, and his kicking record is excellent," said Robinson.
"He has been brought into the squad and I am sure he will be relishing the fact. If he gets picked (for the team), I am sure he will give his best."
Robinson also praised the commitment and professionalism of both the players and staff that went on last summer's Lions tour of New Zealand.
"It is about pulling together (on a Lions tour) to achieve a goal. If you have got a problem, then go to the person you've got a problem with and sort it out.
"I know a lot of the (Lions) management from previous occasions, and how they operate, so for me it was easier to deal with.
"Everyone has got their opinions. Lots of players and back-up staff were taken to New Zealand, and they've got different personalities and different ways of doing things.
"Part of a Lions tour is to try and gel all those different characters and personalities to become one.
"There will always be times when you disagree with views of certain people, but the main thing is that everyone has to do their job.
"I respect that people tried to do it the way they wanted to do it, and unfortunately, we weren't successful.
"It is a very tough job playing against New Zealand, the form team in the world, and coming together for such a short period of time was always going to be a big ask, but I felt that everyone there put everything into it."