Two changes to the Chiefs team for Saturday's semifinal were straightforward - the fit-again Sam Cane and Seta Tamanivalu were always going to earn selection.

But the third and final alteration is where the intrigue lies ahead of the clash against the Hurricanes in Wellington, with Tawera Kerr-Barlow replacing Brad Weber in the No 9 jersey.

The two 25-year-olds have, when healthy, split the minutes at halfback this season. Removing Kerr-Barlow's injury-related absences and they have each made five starts in the 10 games in which they've both been available.

Weber ran on in the quarter-final victory over the Stormers, Kerr-Barlow earned the nod in the previous week's pivotal defeat to the Highlanders. So, in a pure meritocracy like professional sport, why has the job been so evenly shared?


Aside from the fact both are exceptional players, counting among the top four halfbacks in the country, the coaches' preference can indicate what kind of plan they are trying to implement.

Last week, against the Stormers, the Chiefs wanted to stretch their physically-imposing opponents, aiming for a high-tempo game with an emphasis on width to unlock the South Africans' defence. So they opted for Weber, a smaller man who excels in speed to the ruck and support play, and he lit the fuse under his side's explosive attack as they romped to a record win.

This week, against the Hurricanes, the Chiefs are anticipating a tighter game in score and style, and want a player who thrives in sniping around the fringes and snuffing out the same strategy from the opposition. So they chose Kerr-Barlow, who has about 15 kilograms and 15 centimetres on his rival, and uses that frame to dominate the edges on both sides of the ball.

His selection - aided by a forecasted wet evening at Westpac Stadium - pointed to the Chiefs not abandoning their expansive attack but perhaps restricting some of their enterprise in deference to both the Hurricanes and the weather.

"We're pretty lucky that we have a couple of great options," said coach Dave Rennie. "They both pass well and kick well but there are slight differences, and we felt Tawera's physicality and the strength of his defensive game was going to be really important.

"There's likely to be fairly average weather in the weekend and it could be a bit of a battle of attrition around the fringes. So we felt Tawera would be important for us."

Weber will likely still prove his own importance given how Rennie has switched between the players in search for an altered approach - in the 10 matches featuring both men the substitute's average cameo length has been 21 minutes.

But even knowing he might have the chance to change the course of the semifinal, with his speed potentially crucial against a tiring defence, Weber acknowledged it was difficult to share the jersey he wanted to own.

"I understand it, because we're two different players," he said. "It's a little bit of horses for courses type of mentality, in terms of what kind of game plan or what they want out of the halfback that week.

"I'm sure Tawera would tell you the same thing - it can be tough at times it terms of consistency but I think we complement each other and it's working really well."