The 23-year-old Henley stunned the golfing world with a spectacular display of clutch putting and ice-cool nerves as he clinched his maiden title on the US circuit by three shots at the Sony Open in Hawaii on Sunday.
Though the American has barely slept a wink since his breakthrough victory, he is excited to be back in action on the golf course this week at the 72-hole pro-am celebrity event in the California desert.
"The last few days have been kind of crazy for me," Henley said while completing his preparations for the third event on the 2013 US PGA Tour. "I have just been so excited about everything that's going on.
"Sunday night I flew from Honolulu to LA overnight and I didn't really sleep at all. Then last night I just caught myself waking up a lot during the night, feeling like a little kid.
"I just got an invite to play in the Masters and (a three-year-exemption) to play on the (US) PGA Tour and I'm still just trying not to take it for granted. And I'm just really excited to be here and play another golf tournament this week."
Henley became the youngest champion at the Sony Open after storming home with five consecutive birdies to fire a seven-under-par 63 on the tree-lined layout at Waialae Country Club.
He mixed eight birdies with a lone bogey in that final round to post a record 24-under total of 256 in the US PGA Tour's first full-field event of the season.
Henley has since been showered with congratulations by his peers and his friends, and was especially humbled after receiving a 'Tweet' from nine-times Major champion Gary Player.
"That was pretty cool," Henley smiled. "And I got a lot of texted messages from friends back home and I'm just going through those. Answering those has been pretty special."
Though still feeling fatigued after the heady heights he scaled last week in Honolulu, Henley was confident he would be ready for Thursday's opening round at the Humana Challenge.
"I think one more good night of sleep's going to help," he said. "I'm probably not quite as well rested as I was last week, but I still have a lot of adrenaline and I'm really, really excited to go play. I'm definitely ready."
While Henley is trying to catch up on his sleep, fellow American Mickelson is battling to shake off a lingering "flu-like illness" that has hampered him for the past 10 days.
However, tournament officials said Mickelson was planning to tee off in the opening round at an event he has long relished playing.
The American left-hander is the leading all-time money winner at the 72-hole pro-am celebrity event, previously known as the Bob Hope Classic, and won the title in 2002 and 2004.
"It's a great place to start the season because we have usually very calm conditions, we have great practice facilities and three wonderful golf courses," Mickelson said on a conference call earlier this week.
"And it's a great place for me to start the season because it allows me to work on my game before and after each round. I have a small place out there at one of the clubs that I'll stay in.
"After each tournament round I go practise and put in that time to build a solid foundation for the rest of the West Coast (swing), as well as the rest of the season."
Also competing this week are FedExCup champion Brandt Snedeker, US Open winner Webb Simpson, fellow US Ryder Cup players Zach Johnson and Matt Kuchar and 21-year-old Japanese Ryo Ishikawa, who is appearing at the event for the first time.
Compatriot Mark Wilson is back to defend the title he won by two shots last year.