Former All Blacks captain Sean Fitzpatrick believes Ireland prop Jack McGrath should come into the starting Lions team in place of Mako Vunipola for the series-deciding Test at Eden Park.
Vunipola gave away several of penalties and was sin-binned for an illegal clearout of Beauden Barrett in the second Test victory, as he was one of the worst culprits of the Lions' noticeable lack of discipline.
Fitzpatrick admitted on Wednesday New Zealand are "tense" ahead of the third Test on Saturday, but added the Lions should make a change themselves at loosehead to improve their chances.
"Vunipola has had a good series but gave away a lot of penalties, cynical too I think some of them," Fitzpatrick told Sky Sports News HQ.
"They need to tighten that up, and I would probably start with McGrath in this Test match.
"The intensity in that first 20, 30 minutes will be huge and you'll need a good set-piece, and I think McGrath just offers a bit more of that.
"Vunipola off the bench with 30 to to go would offer huge impact, and that's what they need."
Another area of selection contention appears to come in the second row, with Courtney Lawes pushing Alun Wyn Jones hard for a starting place.
After a poor display alongside George Kruis in the opening Test defeat, many had expected Jones to be absent from the second Test.
Gatland kept faith in his Wales skipper, however, starting Jones with Maro Itoje despite powerful displays by Lawes and Iain Henderson on tour.
After a much-improved display in Wellington, Jones was replaced by Lawes just before the hour mark, with the England lock then having a big impact on the match with his power and carrying.
Fitzpatrick, who was skipper of the All Blacks the last time they lost a second Test to the Lions in 1993, added he thinks the tourists need Jones' experience on Saturday, however.
He said: "I think I'd leave Lawes where he is. I thought Alun-Wyn Jones played very well last week, a real step up from where he was in Auckland. and he's got the experience.
"This is like a World Cup final, so they need as much experience on that park."