After being evaluated, Dietrich got up and remained in the game. It was the third time in his first 18 spring plate appearances he's been hit by a pitch.
Dietrich started at third base in Miami's 4-0 win over the Nationals at Space Coast Stadium.
"I didn't think it hit him in the head because I didn't hear the helmet or anything," Miami manager Mike Redmond said. "But any time you get up around the neck area, it's scary, especially after what we went through last year. Thankfully, he's OK. He's a little sore, but he will be fine."
As an organization, the Marlins are still recovering from Giancarlo Stanton being struck in the face by a pitch on Sept. 11 in Milwaukee.
On Tuesday, Dietrich hit a walk-off home run in Miami's 2-1 win over Washington in Jupiter.
In his third season with the Marlins, Dietrich has endured more than his share of plunkings. In 416 plate appearances, he's been hit 17 times.
"I don't know if he's on that plate a lot, but yeah, there always seems to be one guy who is the magnet out there," Redmond said. "It's definitely him."
Joe Frisaro is a reporter for MLB.com. He writes a blog, called The Fish Pond. Follow him on Twitter @JoeFrisaro. This story was not subject to the approval of Major League Baseball or its clubs.