Mickelson won the event at Castle Stuart last year before going on to triumph in the Open at Muirfield seven days later and McIlroy believes the 2014 event at Royal Aberdeen is perfect preparation for the following week's major at Hoylake.
McIlroy, whose previous Scottish Open experiences came at Loch Lomond, said: "I can think of no better preparation for the Open, especially on a respected course like Royal Aberdeen. There will also be so many similarities I can bring to the following week's Open Championship. Phil winning the double last year made me realise that the Scottish Open is more than good preparation for the Open - he showed it was possible to win both weeks.
"You can play as much golf on links courses as you want but, until that's in a competitive environment, you can never tell how ready your game will be. It really is so important, then, to get some competitive golf on a true, challenging links."
Mickelson has already confirmed his participation in the event.
Jimmy Walker held his nerve to win the AT&T Pebble Beach National Pro-Am by a single shot, his third win of the PGA Tour season. Having had a six-shot lead gradually eroded on the final day, he three-putted the 17th and, needing a closing par, missed the fairway and chased his first putt five feet past the hole. He had to hole the one coming back to avoid a play-off with Dustin Johnson and Jim Renner and, though the ball threatened to dive left, it dropped to secure the win.
Hunter Maham had been his nearest challenger going into the final round but he could manage only a 72 as his Ryder Cup colleague Johnson and Renner came to the fore.
Russell Knox, the 28-year-old Inverness exile, finished joint 27th and earned $46,860, taking his earnings from eight starts as a rookie on the PGA Tour to $425,178 for 50th on the money table. Martin Laird is 85th with $234,013.
Knox, who is now based in Jacksonville Beach, Florida, after four years at Jacksonville University, has never played in his native Scotland as a professional but says that he will come to Royal Aberdeen for the AAM Scottish Open in July if he has secured his PGA Tour card for 2015 as looks likely to be the case.