Buriram United coach Ranko Popovic has been suspended for three months for attacking an opponent, the Football Association of Thailand (FAT) said on Tuesday.
The ruling was made by the FAT disciplinary committee after Popovic slapped in the face of Bangkok United physio Andy Schillinger following a recent Thai League 1 match at I-Mobile Stadium.
The incident took place in the tunnel and was witnessed by fourth official Nitipoom Kullabut.
Popovic, whose team won the match 2-1, also faces a fine of 40,000 baht.
Buriram said they will appeal against the decision.
If the punishment stands, Popovic will miss nine Thai League 1 matches, including one against bitter rivals SCG Muang Thong United at SCG Stadium on July 9 which could decide the title.
Muang Thong and Buriram are joint leaders at the end of the first half of the season. The second leg of the campaign will begin June 17.
Meanwhile, Thai League 1 side Ratchaburi have signed DR Congo defender Joel Sami as a replacement for Carlos Santos who faces a long-term injury lay-off.
The 32-year-old has played for Spanish club Valencia and French side Nancy.
"I don't know much about Thai football. I watched Ratchaburi play Bangkok United recently and feel the pace of play here is very fast,'' said Sami. "I hope I can help strengthen the team's defence."
In another development, Muang Thong United unveiled their new signing Totsawat Limwannasatien.
"Muang Thong have many national team players so I have to work hard to be selected by coach Totchtawan [Sripan]," the midfielder said.