WATCH | Jean-Philippe Mateta being kicked in face by Millwall goalkeeper Liam Roberts shocks football world

Millwall goalkeeper Liam Roberts was sent off just eight minutes into Saturday's FA Cup game against Crystal Palace after a wildly reckless challenge on star striker Jean-Philippe Mateta. 

Roberts rushed outside the 18-yard box and leaped to clear a long ball but his high left-footed follow-through struck Mateta in the side of the face. The forward was carried off on a stretcher as a consequence of the foul.

Mateta remained on the ground for several minutes and needed lengthy medical treatment before he was fitted with a neck brace and carried off the field toward an ambulance.

So far what we know is, he's got a bad gash behind his ear and a head injury," Palace chairman Steve Parish told the BBC during the halftime break. "Obviously he's at the hospital, so we hope for the best.

Referee Michael Oliver initially did not even show Roberts a yellow card despite being only a few yards away from the incident but then brandished a straight red after being called over by VAR to review the incident on a pitchside monitor.

In all the time I've watched football I've never seen a challenge like it," Parish said. "That is the most reckless challenge on a football pitch I think I've ever seen.

Mateta is Palace's leading scorer with 12 Premier League goals this season.

Premier League side Crystal Palace took a 2-0 lead through an own goal by Japhet Tanganga and an easy tap-in from Daniel Munoz, but Millwall got back in the game when Wes Harding scored just before halftime. Eddie Nketiah, who came on for Mateta, added the third with a looping header in the 81st.