In the second period of Detroit's Game 6 loss to Tampa Bay, Kronwall laid out Kucherov with a big hit that on replay showed forearm-to-head contact.
"I thought it was a clean hit at the time," Kronwall said Monday night.
Referees Dave Jackson and Steve Kozari did not call a minor penalty on the play. Kucherov left the game but returned for the third period and said he was OK.
"It's a hit," Kucherov said. "I'm not going to cry now. It's part of the game. That's why we play here."
Lightning coach Jon Cooper said he didn't see Kronwall's hit on Kucherov because of where it happened on the ice.
"The refs didn't call a penalty so it must've been OK," Cooper said.
The six-foot, 194-pound Kronwall has a reputation as a ferocious hitter but has never been suspended in his NHL career.
The NHL's department of player safety hadn't even held a hearing in the first round with six of the eight first-round series wrapped up, so there have been no suspensions so far in the playoffs.
Game 7 is Wednesday night at Amalie Arena in Tampa.