The 26-year-old Kriel will take the captain's armband into a cauldron-like Ellis Park after Whiteley was withdrawn due to a calf problem.
Whiteley's calming influence may be missed as the hosts bid to reach their first Super Rugby final, having failed in the semi-finals twice in 2000-01 in their previous life as the Cats.
The game could well be decided by fine margins as it pits the competition's best attack against its most dominant defence, according to Opta statistics.
The Lions average more points, tries, defenders beaten and metres per game of any team in Super Rugby this season, while their New Zealand opponents have conceded the fewest points and tries on average, while making the most tackles.
Highlanders scrumhalf Aaron Smith believes part of the Lions' success is due to their playing like New Zealanders.
"They play a real positive game of footy," he told reporters.
"One thing you have to respect about the Lions is they play their footy for the full 80 (minutes). I've seen a lot of footage of them just quick-tapping in the 76th minute, they don't stop until the whistle goes."
The Highlanders must do without Tongan prop Siua Halanukonuka, who was injured in their 15-9 quarter-final win over Australia's ACT Brumbies, as well as flanker Shane Christie (neck) and hooker Liam Coltman (toe).
Coach Jamie Joseph has brought James Lentjes in for Christie while lock Alex Ainley replaces Luke Whitelock, who moves to number eight.
The reigning champion Highlanders have never beaten the Lions at Ellis Park in four previous visits, their last a 28-23 defeat in 2015.
The teams have clashed in New Zealand already this season with the Dunedin-based side winning 34-15 in March.
(Editing by Greg Stutchbury/Ian Ransom)
