The good news is it won't be vegetarian fare. The bad news is it won't be Seve Ballesteros' favorite meal, either.
Mickelson hoped to lure Ballesteros back to Augusta for the first time since 2007 by letting the two-time winner select the menu, but the ongoing recovery from brain cancer will likely prevent him from making the overseas trip in April.
"I just sent him an email saying that if he were able to come and feeling healthy enough to be able to make this tournament, I would love to have the dinner be something that he would like, like a Spanish dish of paella or whatever he thought would be appropriate," Mickelson said. "I wanted to kind of honor him.
"But unfortunately I don't think he's going to be able to make it, given some emails we've received, I don't think he's planning on attending. So our thoughts and prayers are going to be with him that evening."
Ivan Ballesteros, the nephew and manager for the European Tour icon, said his uncle was flattered by the gesture.
"He was very happy to hear from Phil and he very much appreciated the invitation, obviously," Ivan said.
Ballesteros was diagnosed with cancer after collapsing in the Madrid airport in October 2008. Over the next few months, he underwent four surgeries and chemotherapy to destroy a malignant brain tumor.
He hoped to be well enough last summer to travel and compete in an exhibition with other British Open winners before the start of last year's Open Championship at St. Andrews. But a few weeks before the event, he sent his regrets and withdrew based on his doctors' advice.
Santander, Spain, to Augusta would be an even more arduous undertaking.
"Seve at the moment is still in his recovery process, and it's a long recovery process," his nephew said. "He has to treat things a little differently. He is a little bit tired, but he is focused on his recovery. He's not traveling at all except to Madrid when he needs to see doctors. It's going to be very difficult for him to go all the way there."
That's something Mickelson understands, as his wife and mother have been treated for breast cancer since June 2009.
Mickelson and Ballesteros share a mutual appreciation for each other and the way they play the game with a combination of fearlessness and panache.
Ballesteros' flamboyant play in winning the 1980 Masters provided an early inspiration for Mickelson. That childhood memory is often rekindled when he returns to Augusta National and drives down Magnolia Lane.
"Like you wouldn't believe," he said. "It reminds me of when I was a kid. It reminds me of when I was 10 years old watching Seve Ballesteros win in 1980 and saying to my mom, 'I want to win that tournament. I want to be like that and win this event.'
"It reminds me of dreams that I had as a child, and I feel like Augusta National and the Masters Tournament gives every kid in the game of golf who dreams of playing professionally, dreams of winning major championships, something to strive for, something to dream about. And when we arrive at the premises at Augusta, it exceeds our dreams, which is hard to do."
Mickelson's third Masters victory last April, the aggressive manner in which he played and the emotional embrace with his wife inspired Ballesteros as he watched it on television. He had recently gotten a Labrador puppy and decided to name it "Phil."
"It's a new dog, so nice and strong and good looking," Ballesteros said in a BBC interview last summer. "Labrador is a fantastic dog. I have to look for a name, and Phil Mickelson just won the Masters."
In August, Mickelson announced he had adopted a vegetarian lifestyle to try to combat symptoms of psoriatic arthritis. He adhered to a strict diet for five months before reintroducing protein into what he says are more healthful eating habits.
"Well, we knew that was doomed from the beginning," said the four-time major winner famous for his love of Five Guys burgers.
That means Mickelson plans to give his fellow Masters champions what they crave.
"I learned one thing over the years: Many of the past champions, they love beef and they love meat," he said. "And because of that, I want to honor kind of the past champions at Augusta. I plan on having a trio of different meats, whether it be bison or venison or just (beef) filet. I was thinking about kind of honoring the guys with a bunch of different meats, as well as a lot of green vegetables."