Wessels will miss for South Africa's autumn internationals.
South Africa front-rower Wessels has received a ban of nine matches for touching opponent Josh Murphy's genitals during the Blue Bulls' United Rugby Championship win over the Irish province.
The altercation occurred in the 18th minute of the Bulls' 28-27 win against Connacht on Friday, with opposing player Josh Murphy being shown a 20-minute red card after responding aggressively by hitting Wessels on the head area.
After the Connacht player reported the incident to the match official, the contact was reviewed by the TMO, who concluded insufficient clear footage.
Wessels stayed on the pitch until he was substituted in the second half of the match.
While the United Rugby Championship confirmed that Murphy's temporary sending-off was rescinded by a disciplinary panel, the Springbok was deemed to have violated the code of conduct, which declares:
"A player must not do anything that is contrary to the spirit of good sportsmanship. Such behavior covers grabbing, twisting or squeezing the genitals."
The panel concluded that the incident met the red card threshold and warranted a 12-week suspension, the minimum ban under World Rugby rules for such an offence.
However, Wessels' suspension was shortened by 21 days because of his good conduct prior to and at the proceedings and his good record.
The forward and the Bulls are entitled to challenge the decision, but currently, the ban will rule the 24-year-old out of the South African national team's fall internationals against Japan, Les Bleus, Italy and the Irish team.
Wessels will additionally be absent for the his club's URC games against Glasgow, the Emirates Lions and the Cell C Sharks, as well as European cup fixtures with Bordeaux and Saints.
The prop has earned 10 caps for the Springboks and was included in their tri-nations champion team over the summer.
The Connacht player, in contrast, is available to play against Munster in Saturday's inter-provincial derby after being cleared.