Piniella managed during the Mariners' most successful years, including a 116-win season in 2001, and he was responsible for all four of the franchise's playoff appearances and seven of its 11 winning seasons.
Piniella said he ate lunch with club executives Howard Lincoln, Chuck Armstrong and John Ellis on Tuesday, bringing back memories from his tenure in the Emerald City.
"It's wonderful, a wonderful city," Piniella said. "I had 10 really good years here. Lots of pleasant memories, not only baseball-wise, but friends."
He said he regretted not being able to see Ken Griffey Jr., his former star player who retired this season, and added he planned to call him soon to catch up.
"When I had him here my first five or six years, [Griffey was] absolutely the best player in baseball, in my opinion," Piniella said. "Great hitter, and just as great an outfielder, and he enjoyed playing the game. He was as productive as any player. I thought he and Barry Bonds [were the best]. I choose our guy because he played center field and played it so well."