On a Marlins team that finished in last place, Vazquez won all five of his starts in September, and his ERA in the month was the lowest for qualifying starters (0.71).
Also in September, Vazquez set a Marlins' scoreless-innings streak record that reached 29.
So why retire?
"People say, 'You're pitching so well,'" Vazquez said after his complete-game win over the Nationals on Tuesday. "I'm glad I'm pitching well because it would be tough retiring on a bad note. At least, I'm throwing well."
From the way he sounded in recent weeks, Vazquez appears ready to step away from the game.
Asked if Tuesday was his last start, the Ponce, Puerto Rico, native said: "It could be. I'm going to make the decision, hopefully by December. Maybe before."
The Marlins signed Vazquez as a free agent last November, and at the time, he wanted a one-year deal because he already was thinking about retiring.
After a slow start, Vazquez made a remarkable turnaround. He was 5-8 with a 5.23 ERA in his first 18 starts. And he finished his year at 13-11 with a 3.69 ERA.
Since the All-Star Break, Vazquez was 10-4 with a 2.15 ERA.
In September, two of his last three starts were complete games, including his last appearance.
And on Sept. 21, Vazquez blanked the Braves for seven innings.
The reason Vazquez may not return to the mound is to spend more time at home.
"Just family time," he said. "Spend time with my kids. I've been blessed to be in the big leagues for 14 years."