James Lowe could miss Leinster's crunch European games this month after being cited for his red card tackle on Andrew Conway last Saturday.
The Kiwi collided with the Munster winger in the 26-17 defeat at Thomond Park, leaving Leinster with just 14 men for the entirety of the second half.
Lowe chased the same high ball as Conway, but did not get off the ground and caught the Munster man below the waist, sending him tumbling to the ground head first.
A disciplinary hearing will take place this Wednesday, with Lowe's involvement in the clashes with Toulouse and Wasps on the line.
Johnny Sexton and Tadhg Furlong have not been cited following the tempestuous defeat in Limerick.
Furlong was sent to the sin bin after his chest-to-head contact with Chris Cloete, but the Ireland tighthead was spared any further punishment after the citing commissioner agreed with referee Frank Murphy that the contact was 'awkward' but not intentional.
Johnny Sexton, who was involved in multiple altercations on the pitch but the Leinster skipper has avoided any potential costly citing.
Should Lowe be banned, Leo Cullen would be short of backline options with Dave Kearney, Joe Tomane and Fergus McFadden also out injured.
But Rob Kearney has made a well time return to fitness, and if the full back is available against Toulouse, Cullen could look to Jordan Larmour, Adam Byrne or Rory O'Loughlin on the wings. Barry Daly and Jack McGrath have also returned to training and are available for the visit of Ulster on Saturday.