In the 10th inning of Game 4 of the National League Championship Series, Machado appeared to drag his left foot as he was running down the first base line to deliberately make contact with Aguilar.
After the game, Brewers right fielder Christian Yelich called Machado a "dirty player" and said he "has a history of those types of incidents," per Stephen Watson of WISN 12 News:
Machado denied he purposefully kicked Aguilar.
"I was trying to get over him and hit his foot," he said, per ESPN.com's Arash Markazi. "If that's dirty, that's dirty. I don't know, call it what you want."
Last year, Machado received criticism after his spike caught Boston Red Sox second baseman Dustin Pedroia's left knee while the then-Baltimore Oriole slid into second base. MLB suspended him for five contests in 2014 after he threw his bat down the third base line in a game against the Oakland Athletics.
In Game 3 of the NLCS, the umpiring crew called Machado out for interference while he was sliding into second. Upon a video review, the umpires determined he had intentionally slid away from the bag to disrupt Orlando Arcia's throw to first.
Machado scored the winning run for the Dodgers on Tuesday night, coming around from second on a 13th-inning single by Cody Bellinger.
The four-time All-Star is 6-for-17 with a home run and three RBI in the series.