Southampton boss Mark Hughes has claimed that Chelsea defender Marcos Alonso set out to hurt Shane Long in Saturday's Premier League meeting at St Mary's Stadium.
Alonso appeared to catch Long high on the back of his leg with a studs-up challenge, but referee Mike Dean did not award a foul, let alone send the Spaniard off.
While Long was on the ground feeling the effects of the tackle, Saints midfielder James Ward-Prowse was booked for protesting.
Hughes, whose side relinquished a two-goal lead to lose 3-2, was critical of the match officials and questioned how they missed the tackle.
"In the last two games against Arsenal and Chelsea I've seen encouraging things but also things that will damage us in the coming games if we don't learn from them," Hughes told BBC Sport.
"I've got a group fighting to get out of this situation but we've not taken points where we should've done again.
"I've seen Marcos Alonso's tackle on Shane Long again - it's a clear red card and clear intent to hurt Shane. It could've broken his leg. There were three officials within five to 10 yards so how each of them missed it is a mystery to me."
Saints remain three points adrift of safety with just five games remaining in the campaign.
No Data Analysis info
