Imagine a pro golfer being told the hole will be made smaller, or a tennis player who finds his racquet has been swapped for a table tennis bat.
That's the scenario facing new Kookaburras goalkeeper Tristan Clemons in this week's four-nations hockey tournament in Perth with new rules in which the goals have been made a metre wider.
It is among several changes to normal rules for the Lanco International Super Series, designed to produce faster, more fan-friendly hockey.
But it leaves 23-year-old Clemons going into his international debut seemingly at a major disadvantage.
Yet the Western Australian believes there's a risk-reward scenario at play which could work in his favour if he can shine on the big stage, defending a bigger goalmouth and, hopefully, earning the biggest of prizes with a trip to next year's Olympics.
"It's a chance for me to come out and make some big tackles and some big saves, so I'm looking forward to it," Clemons said.
"I've only had two sessions in the goals so far. We played 20 minutes of the format at training and the score ended up being 6-4 in the end.
"If we're playing 30 minutes (two 15-minute halves), they're going to be some high scores.
"I'll be looking to come out and play more like a defender, rather than sit back and be a shot-blocker and that'll bring us into some new skills we'll use."
For a player who will be confronted with size issues for the remainder of this week, strangely in his day job, Clemons works with the smallest of the small.
He is involved in nanotechnology, doing a PhD in developing medical technology from the tiniest of particles that can be absorbed into the bloodstream, aimed at finding cures for diseases such as cancer.
Kookaburras coach Ric Charlesworth helped develop the Lanco International Super Series format, which involves nine players a side rather than 11 and changed penalty corner and penalty stroke rules.
Both the Kookaburras and their female counterparts, the Hockeyroos, will take part in men's and women's tournaments.
Australia's men play Pakistan in their opening match on Thursday, followed by matches against New Zealand and India.
The Hockeyroos play Malaysia and India in a three-sided tournament, with all finals to be played on Sunday.