Arenado eventually walked to first base and remained in the game before being removed in the fifth inning with a left forearm contusion.
Cubs manager Joe Maddon was asked postgame about Arenado's response to the plunking.
"Right now, we lead the league in getting hit by pitches," Maddon told Patrick Mooney of The Athletic. "And our guys go to first base."
"We get hit a lot," the veteran skipper added, according to Mooney. "Rizzo gets hit a lot. (Kris Bryant) gets hit a lot. I've always (said), 'You got two options. Go to the mound or go to first base. But don't sit there and jabber. Make up your mind. Do one or the other."
The Cubs ranked among the league leaders in times hit by a pitch entering Wednesday's action, sitting tied for third with four other teams at 34. The New York Mets and Minnesota Twins have been hit more often, with 36 and 35, respectively.
"I think you can ask both teams, it's annoying getting hit, in general," Rizzo told Mooney. "When you think it's intentional, it is what it is, and you just move on."
The Cubs routed the Rockies in the series finale, winning 10-1 after dropping the first two games of the three-game set. The two teams don't meet again for the remainder of the regular season.