Heck, it might have helped.
"I was walking to the fourth hole and it looked like there was a thousand people following him," Day said. "It took a little bit of pressure off my shoulders knowing that the good majority of the fans that were following me were close friends and family."
Spieth was within three strokes of the lead on the final nine holes of the Byron Nelson Championship on Sunday, then drifted back into a tie for 16th. It's still an incredible finish for a kid who last week was playing in the state high school tournament.
While Spieth likely will be remembered as the big winner of this week, it is Day's name that will go up on the champion's wall behind the oversized statue of Nelson near the first tee.
Already in the record books as the youngest winner on the Nationwide Tour -- he was 19 -- Day had to wait until he was 22 for this breakthrough.
"It's been a hard, tough road," Day said. "I've had a lot of negative thoughts go through my head. ... I would always think of what jobs I could do if I didn't secure my card. ... I'm glad I just stuck through it."
He's glad he stuck through this week, too.
Day nearly withdrew Thursday morning because he felt so ill. He wound up tied for the lead after the first round and was near the top all week, even while scuffling through a 2-over 72 Sunday.
He thought he might have blown it when his approach to the final hole went into the water. But he got a reprieve when playing partner Blake Adams -- who said he didn't see Day's ball get wet -- knocked his ball into the water, too.
Day salvaged a bogey, while Adams, a 34-year-old Tour rookie, took a double bogey and dropped into a tie for second with Brian Gay and Jeff Overton. Gay shot 7-under 63, the best round Sunday by three strokes.
"I wasn't nervous," Adams said. "I just didn't play well."
Spieth will be headed back to his junior year of high school Monday with a whole lot to talk about.
He became the sixth-youngest player to make the cut on Tour, then said he was serious about wanting to win. When he shot 3 under Saturday, it wasn't so farfetched.
Then came back-to-back bogeys early in the final round and a shot out of a fairway bunker that angered Spieth so much, he pulled back with his iron, ready to throw it at his bag.
But a deft chip led to a par putt. And then the kid turned everything around.
Three birdies and three near-misses left him standing on the 11th tee at 7 under while the leaders were at 10 under. Imagine what it would've been like had those three near-misses fallen.
A few holes later, he started backing up again -- a bogey, then a double-bogey. Yet he bounced back once more, too, with a birdie on the next hole and knocking his tee shot to the par-3 17th just 14 feet from the cut.
Alas, Spieth missed that putt and a par putt of about the same distance on No. 18 for a closing bogey. He walked off to a loud ovation, a handshake from playing partner Corey Pavin and a hug from Peggy Nelson, widow of the tournament's namesake.
"It was awesome ... the entire round, the entire week," Spieth said. "Starting the week, I definitely would've taken a top 20, in a heartbeat. Obviously now, looking back, being a competitor, I look back at the mistakes I made that didn't give me an opportunity to win."
Spieth, the reigning U.S. Junior Amateur champion, would've made $91,185.71 had he turned pro this week. But he's planning to wait through another year of high school, then attend the University of Texas.
At least, that's the plan right now.
"I wouldn't say [this week] changed me fundamentally," he said. "I can't wait to get back out there and do it again."
He's already gotten a sponsor's exemption to play in Memphis next month. First, he'll play an American Junior Golf Association event in Arizona next week. Then he has finals.
Day's next event is the Colonial in Fort Worth, where he lives. As if that isn't enough of a boost, he also seems to have conquered the illness that's befuddled him since the opening week of the season.
It's been diagnosed as swine flu, bronchitis and allergies. Medicines to fight those things caused so many problems he withdrew from a tournament and went to the emergency room. Finally, on Monday, another doctor called it a chronic sinus infection, and Day is convinced that's right.
But even that diagnosis caused a problem. A heavy-duty shot and other antibiotics left him so queasy Thursday morning that when he went to get an umbrella from his car, he thought about driving home. He might not have made it through that first round without a nearly 4-hour delay because of threatening skies, which let him sit, relax and drink lots of water.
"I still have blocked ears and some gunk in the back of my throat and my nose," he said. "But it's dried up a lot more than it was."
Day was as amazed as anyone by Spieth's success, which is saying something.
Hailed as another Tiger Woods while growing up in Australia, he began playing PGA Tour events at 18. He played 65 tournaments before finally winning one, but figures the experience was worth it, admitting he got a bit lazy after having success and money at a young age.
His advice for Spieth?
"Keep at it, keep learning, keep playing a lot of tournaments and try and win as many as you can," he said. "Make [winning] a habit and keep pushing through, no matter what happens. As long as you push through those hard experiences and work hard, you'll come out on top. It will all work itself out."