Video footage has emerged showing him apparently striking Atletico Madrid defender Marc Pubill during the post-match celebrations that followed Tuesday's 1-0 semi-final win at the Emirates Stadium.
The incident occurred in the moments after the final whistle, when a group of Arsenal players including Viktor Gyokeres, Myles Lewis-Skelly and Cristhian Mosquera were celebrating near the centre circle. Pubill, 22, approached the group and shoved Gyokeres from behind as the Swedish striker was linking arms with teammates.
Jesus reacted immediately, stepping in and appearing to make forceful contact with the side of Pubill's face, sending him backwards before Mosquera intervened to guide Pubill away and Rice and Lewis-Skelly stepped in to defuse the situation.
The footage, circulated widely on social media within hours of the final whistle, shows the incident clearly. Jesus was an unused substitute throughout the evening and had played no part in the match itself.
UEFA confirmed they are examining the official post-match reports from the tie. The governing body's Disciplinary Panel will reach conclusions based on a Match Delegate's report. If the incident is flagged for formal proceedings, Jesus could face a ban that would rule him out of Arsenal's final against Paris Saint-Germain on 30 May — a match that represents the club's first appearance in a European final since 2006.
The incident was one of several flashpoints after the whistle. Atlético manager Diego Simeone had earlier shoved Arsenal sporting director Andrea Berta near the technical area in the 95th minute and was separated by the fourth official. Pubill had already been fortunate to escape a second yellow card earlier in the half for a foul on Gyokeres.
Jesus has made 19 appearances in all competitions this season, contributing five goals and five assists in a campaign disrupted by injury. He is understood to be one of several players Arsenal are prepared to sell this summer as Mikel Arteta reshapes his squad, with the club holding a preferred alternative to Atlético's Julián Álvarez as their top striking target.