Faingaa was penalised with a red card in the 61st minute when he came face to face with Mattys Basson and lent in with his forehead.

The contact and impact was minimal, but it didn't look good and Faingaa was cited post match for striking with the head.

The unpredictable Super Rugby judiciary could slap Faingaa with a ban as early as Sunday night, but if he fights any charges he'll face the tribunal at 5pm on Monday.

The Brumbies managed to rally in Faingaa's absence and came from behind to snap a five-game losing streak with a 38-28 triumph at one of the most intimidating venues in world rugby.

But they now face a wait to see if they will be hit with more Super Rugby tribunal inconsistencies. Winger Chance Peni was suspended for seven weeks for a high tackle earlier this year and Rory Arnold was ruled out for three weeks for the same offence last week.

Faingaa's incident occurred after he was penalised for going off his feet at a ruck. When he stood up, the Bulls players poked the bear and Faingaa reacted.

The timing is cruel given Wallabies coach Michael Cheika - who has been watching Faingaa closely -will name his squad on Wednesday night for a three-Test series against Ireland in June.

Faingaa, 23, has been outstanding for the Brumbies in his debut season, particularly in the past two weeks, after being forced to step up when Josh Mann-Rea's season was ended by injury.

But Brumbies coach Dan McKellar is hoping Faingaa will be available to play against the Japan Sunwolves in Canberra next weekend.

"It was silly from Folau. He had another excellent game up until that point and he's just got to control his emotions there," McKellar said.

"But it caused no harm at all, it was a light tap at best. So you'd like to think he will be available next week.

"I thought Folau's performance last week was excellent and his performance [against the Bulls] was very good. He's a young man in Super Rugby and you've got to understand you can't do what he did.

"It puts the team under pressure. But as an incident specifically, I don't think there's a lot in it."

There was also an alleged eye-gouging incident which officials were keen to investigate but unable to as it occured beyond the most recent stoppage.

A lack of footage is likely to see the alleged offender escape punishment.

The Brumbies were trailing by one point when Faingaa was sent off and fell further behind when Handre Pollard slotted a penalty goal.

It was a case of deja vu for McKellar, who watched his side crumble when Arnold was sent off against the Lions a week earlier.

But this time they found a way to win despite having fewer men on the field, scoring two tries in Faingaa's absence to clinch a crucial 10-point win.

Tom Banks stole the lead with a brilliant try in the 71st minute and then Andy Muirhead sealed the result four minutes later when he finished off a team effort.

"I must admit when we went down to 14 men I did think it was going to happen again," McKellar said.

"But I just knew if kept playing ... we've been encouraging the boys to use their skill, back their ability and not tighten up.

"That was the best thing, when we got down to 14 players we kept playing footy. We scored two excellent tries and that comes from the work they've put in."

Co-captain Christian Lealiifano added: "We've been in that position before, so we spoke about strategy and how we were going to go about it.

"The boys responded really, really well. The pleasing thing was the boys didn't go into their shell, they kept turning up."

Faingaa could find out as early as Sunday night if he faces suspension or is free to continue his impressive rookie campaign.

Fellow rookie Connal McInerney flew to South Africa last week to cover the loss of Robbie Abel, but Abel could be fit to play against the Japan Sunwolves in Canberra this week.

McKellar praised the Brumbies' forwards for muscling up against the Bulls pack and hoped for a repeat performance when they return to the capital.

The club is still waiting on scan results on injured flanker Rob Valetini's knee, but the squad got through the Bulls contest relatively unscathed.

AT A GLANCE

Super Rugby: ACT BRUMBIES 38 (Kyle Godwin, Lachlan McCaffrey, Folau Faingaa, Tom Banks, Andy Muirhead tries; Christian Lealiifano 3, Wharenui Hawera 2 conversions; Christian Lealiifano penalty) bt PRETORIA BULLS 28 (Handre Pollard, Roelof Smith, John-Ben Kotze tries; Handre Pollard 2 conversions, 3 penalties) at Loftus Versfeld, Pretoria, on Saturday night. Referee: Marius van der Westhuizen. Crowd: 8189.