I'm a bit torn on Simpson, as he has been very up and down, but his overall stats at this point probably do make him a favorite. For the season, he's now at #17 in total strokes gained, # 14 in money won, #5 in top 10 finishes. And as for guys who "play well on Sunday", he ranks #7 in final round scoring average. Those are all pretty strong ranks when one considers that a lot of the guys ahead of him are not American.
And I had been leaning towards Haas as a good dark horse, but I think the problem there is that Haas strength is that he is a great ballstriker, something the team already has plenty of. His weakness seems to be putting, which is what the team may need more of. So maybe a guy like Brendon Todd would be a better fit.
Todd I think would be a good fit in team play, so long as you pair him with a strong driver like Mahan or Fowler, or even Ryan Moore. Todd ranks #16 in scoring average, #15 in money leaders, but also #6 in strokes gained putting, #3 in total birdies, and #6 in scrambling. The way the Centenary Course is laid out, 7 of the 10 par fours are odd numbered holes. So basically, in foursomes where you are playing alternate shot, you have a guy like Todd tee off on odd numbered holes, and then he's the guy who will be putting for birdie on most of the par 3s, par 4s, and par 5s.
So given the makeup of the rest of the team, I think Todd would actually be a strong choice, despite not being the biggest name.
And are we assuming Moore is in automatically since Dufner is out? Is that how it works? If so, he's yet another guy who is strong tee to green (#15 strikes gained) but not putting (#72 strokes gained). Looks like he is strong both off the tee and with long approach shots. A Moore + Todd team might play well above expectations in foursomes.