Fitzpatrick beat world No.1 Scottie Scheffler in a play-off to take the RBC Heritage title last week.
It was a second PGA Tour title in the space of a few weeks for the former US Open champion, who also won the Valspar Championship ahead of the Masters, where he finished tied for 18th.
Alex Fitzpatrick, meanwhile, claimed his first DP World Tour title at the Indian Open last month, which secured a spot at the PGA Championship.
The Sheffield golfers will pair up in Avondale, with each team playing four-balls on Thursday (Friday AEST) and then foursomes ahead of the weekend's cut – which the brothers failed to make last year.
Matt Fitzpatrick – now at a career-high third in the world rankings – is hoping to make the most of their time together at TPC Louisiana.
"I think both of our games have changed so much over the last year as well, so it's kind of hard to nail that down, I think," said the 31-year-old when asked how the siblings' games might complement each other in the team format.
"I think we both have certain strengths, and hopefully they can be seen this week. I think for me when we first played here and Alex's driving wasn't his strong suit ... Great iron play, great short game.
"I feel like now ... he's a strong putter and he's a strong driver of the golf ball. Big turnaround. It's really impressive."
Alex Fitzpatrick has six top-20 finishes on the DP World Tour this season and would earn a PGA Tour card should he and his brother finish top of the leaderboard on Sunday.
"I don't feel like we see each other that often. Not as much as we'd like, but kind of every time I play with him and see his game, there's things that you can see are improving" said the 27-year-old.
"With the results he's had this year, you can tell he's doing the right thing."
With Masters champion Rory McIlroy opting not to take part, Shane Lowry – who won the team event alongside the Northern Irishman in 2024 – will partner Brooks Koepka in a marquee group.
American pair Andrew Novak and Ben Griffin will be aiming to be the first team to defend the title, which they claimed by one shot ahead of Danish twins Nicolai and Rasmus Hojgaard.
There are three Australians in the field with Cam Davis pairing up with Geoff Ogilvy, while compatriot Karl Vilips partners American Michael Thorbjornsen.
With AAP.