The first being that it's nothing overly serious and Murray could be the backup tonight. This would obviously be the best possible outcome, but given Murray's lengthy injury history, that might be wishful thinking.
The second is the most serious, where Murray would be placed on LTIR. In that instance, Erik Kallgren, who was injured during the Marlies game last night and has been cleared to return as of this morning, would backup Samsonov tonight. The Leafs may have dodged a bullet with Kallgren if Murray's injury is significant.
Finally, if Murray won't be out long enough to be placed on LTIR, the Leafs will have to bring in an EBUG likely to be Jett Alexander for tonight's game and then Kallgren would join the team on an emergency basis tomorrow.
Should the Leafs need to bring in Jett Alexander for tonight's game, it would be exactly 1 year ago when the Leafs utilized an emergency backup goaltender. Last time around, it was U of T goaltender Alex Bishop, ironically also against the Sens. We should have an update on Murray before game time and we can hope that it is the best-case scenario.