That's what he landed on during his jarring collision with St. Louis catcher Jason LaRue during Sunday's 9-6 loss to the Cardinals.
It all came about when, in the first inning, DeJesus was speeding for home on Jose Guillen's single. He saw LaRue reach up for left fielder Skip Schumaker's throw, and thought he'd try to jar the ball loose.
"I hit him with my forearm, and his mask came off. And when his mask fell, I went, 'boom!,' and landed on his mask. Check the replay. I land right on his mask, I bounce up and fall right on the ground," DeJesus said.
LaRue held onto the ball and DeJesus was out.
DeJesus stayed in the game another inning, but his right rib cage area was hurting from landing on the steel mask. He swung a bat before Monday night's game against the Orioles, but he was still sore.
"The rib area and the whole oblique muscle area, too," he said. "That's why, when you're swinging and trying to get the bat through, it's so sore right now."
He'll continue to get treatment, and hopes to play Tuesday night -- although that's iffy.
LaRue was not hurt, and went on to have a big day in his other job at the plate -- hitting. He hit a two-run homer and a two-run triple.
Royals third-base coach Luis Silverio, who waved DeJesus around third base, said he hadn't seen such a jarring collision in a while.
"When a player does that [rams the catcher], it's usually when they know they're out by a bunch, and they make up their mind that that's what they want to do," Silverio said. "It was a clean play. He wasn't trying to hurt anybody."
Teammate Mark Teahen, watching from the dugout, was impressed by DeJesus' hustle and grit.
"It was a good, hard play, the kind you like to see," Teahen said. "That's the kind of thing that can fire up a team, and it's just too bad that he wasn't safe."
Silverio said he didn't know if DeJesus would have been safe had he tried to slide instead of blasting into LaRue. Neither did DeJesus.
"I thought it [the ball] was on top of the plate, and it's just kind of a bang-bang kind of thing," DeJesus said. "I probably should have [slid], but I just saw his hand go up and I was just going to try to break it up. I was just trying to get a little something going."
All he got for his effort, though, was time out of the lineup and in the trainer's room.
"It's pretty crazy," he said. "I thought I landed on the bat. It was the mask, that's what got me. It's like, what are the chances of landing on someone's mask when you hit him?"
Dick Kaegel is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.