Wales must beat Scotland at Murrayfield to maintain any chance of winning the Six Nations championship, says Neil Jenkins.
Both teams come into the match off the back of defeats, with kicking coach Jenkins saying another loss would be fatal for their chances.
"It's a game we need to win if we want to win the championship, it's as simple as that," he told BBC Wales Sport.
Wales have won nine consecutive games against the Scots since 2007.
"We have to win tomorrow really if we're going to stand any chance," added Jenkins.
"I think it's the same for both sides.
"The third game is massive anyway and can certainly get you back into the mix for the championship.
"So for both sides it's huge and both need to win to give ourselves a chance of getting back into the championship and winning it."
Both Wales and Scotland are on five points after two rounds of matches, four behind leaders England who play Italy in Twickenham on Sunday.
Wales' record points scorer Jenkins believes the game could also be important for the hopes of players aiming to impress British and Irish Lions coach Warren Gatland who will be at the game.
"It's two of the four nations that the players will be picked from and I'm sure there's some selection headaches for Gats at the moment," said Jenkins, a Lions tourist in 1997.
"Any of these games - our game against Scotland, our game against Ireland in a few weeks' time - all these games are going to be massive towards Lions selection and who fronts up and who plays well.
"Tomorrow's game is pivotal in Lions selection, there's no doubting that."