As is now tradition, the Houston Open offers one final opportunity for those playing in the Masters to hone their games ahead of Augusta, and those yet to qualify the opportunity to earn a golden ticket by winning this title.

It's a perfect formula for what is often an enthralling tournament in its own right, but a note of caution is attached. So many of those who have already qualified are here in body but not mind and willing to sacrifice shots if it makes for a perceived better Augusta preparation, and those who haven't must deal with what's at stake if they do work their way into contention on Sunday.

Anyone who watched the Match Play last week might recall that an incentive greater than the title itself managed to stop Justin Thomas in his tracks, but in broad terms that's not something to dwell on. Russell Henley was the latest in a fairly long line of players to win a Masters spot by taking this title and, like so many, found it fairly easy to focus on the job in hand.

While the players without an Augusta ticket - typically quoted at bigger prices - should be judged on merit, the market leaders are to be approached with caution. It's not that they can't win this title - Phil Mickelson is among the well-fancied champions - but the roll-of-honour tells us that they're more vulnerable, collectively, than might've been the case a couple of weeks ago.

- Rory McIlroy,

- Dustin Johnson, Tiger Woods

- Justin Thomas

- Jordan Spieth, Justin Rose

Odds correct at 1230 BST on 27/03/18

For Mickelson, most of the work is now done and he's tasted victory this season already, so whatever happens here he'll head to Augusta in top shape. Similar comments apply to Justin Rose, Rickie Fowler and Henrik Stenson, all of whom skipped the Match Play and will look to shake off any rust here, and of the market principals there's only one who I think will be desperate to get in the mix - Jordan Spieth.

The three-time major champion has endured a difficult year by his absurdly high standards and is yet to hit the frame in eight starts. He's missed two cuts, too, one shy of the number he missed throughout the whole of 2017, and it's fairly obvious that the magic spell he held over his ball on the greens appears to have come undone.

Despite all this, I find him hard to resist. I strongly suspect that Spieth will consider a title challenge here in Houston to be paramount if he's to win a second Masters, and first since that famous meltdown which handed Danny Willett an opportunity. That focus and the lack of it among his peers at the top of the market makes for a tempting proposition at 12/1, and it's only the fact that he says this course really doesn't suit him which makes the decision for me.