Jason Day believes Tiger Woods could contend for his 15th major championship this week – but only if his erratic driver cooperates.

World No.10 Day, who has struck up a friendship with the 195th-ranked Woods, gave a candid assessment after the pair played a practice round on Monday, three days out from the US Open at Chambers Bay.

“If he could get on the fairway, he’d probably be back to where he was,” Day said.

“It’s just ridiculous how good his iron play is right now. It’s really special.”

Woods has gone seven years since winning his 14th major at the US Open at Torrey Pines in 2008 and comes into the event off a difficult start to the year.

Most recently he shot a career-worst 85 at Muirfield Village on his way to an ugly total of 302, finishing last of those who made the cut at the Memorial tournament.

Day is hopeful the man who inspired his career can return to his best but knows it will not be easy for the 39-year-old, especially as he continues to put focus on his young children.

“Who knows what’s going on with Tiger right now?” said Day.

“We’re friends, but I don’t get into his personal life and I don’t want to.

“That’s his stuff and he deserves his privacy.

“But when it comes to golf, it’s very difficult because you could have all the tools in the world, but if you really don’t want to be there or if there’s something that’s off-course that’s playing on your mind… the game is so mental, it’s very difficult to win golf tournaments.

“I’ve learned that very early.

“It really is amazing that some days you’ll come out and you’ll feel like you can beat anyone, and then some days you come out and you’ve got no confidence and you can’t break an egg with a hammer.

“Unfortunately, with Tiger, it’s so hard because he’s done what he’s done in the past and everyone is expecting him to do that still.

“We’re just waiting for him to come back and win those tournaments like it was nothing, hunt down people like he was playing a Wednesday tournament at the country club.

“But will we see it? I’m not sure.

“You’re climbing Mount Everest and he’s fallen off it a couple of times and climbed back up there again.

“I think if he could straighten out that driver, he’d play phenomenal golf, because his iron play and putting is on point.”