The Welsh enigma limped off the pitch just 20 minutes into Cardiff City's 3-1 win at Northampton Town due to an ankle injury.
He was seen leaving Sixfields Stadium with his right foot in a protective boot while walking with the aid of crutches and now head coach Brian Barry-Murphy has confirmed the worst fears of Bluebirds supporters.
"Rubin's timescale will be 10 to 12 weeks. There's a discussion over the next 24 hours about whether he will have surgery or not,” said a concerned Barry-Murphy.
"So, by the time we come to the post-match press conference on Saturday, I'll be able to say that, but I think for the next 24 hours, he's going to make that decision based on what he feels is best and the advice from James Rowland (Cardiff's head of medical services).
"Obviously when an injury of that nature occurs it's very disappointing for Rubin and for his team-mates.
"But once you get over the first couple of days, in our sport, you quickly start to look at the recovery period and the timescales involved and start to see the opportunity that provides for the rest of the squad, but also for him to come back in a much better position physically."
READ MORE: Brian Barry-Murphy Praises Top Spot Cardiff City But Admits Rubin Colwill Blow Likely to be Heavy
This period of absence will serve as a real blow for Cardiff and undoubtedly dent the club's sky-high mood. It will also do nothing to aid their quest to storm to the League One title.
But on a more personal level, it is desperately cruel for Colwill himself given his ability to, at long last, consistently demonstrate his qualities this season.
Prior to Barry-Murphy's arrival at the club in the summer, Colwill had scored just seven goals in 139 league appearances for the club at a rate of almost exactly one in every 20 matches.
Over the same time frame, he had managed just eight assists in the league.
In fairness, his output in cup competitions was far better having scored seven goals in 15 League Cup and FA Cup fixtures - but the reality was that Colwill wasn't living up to his full potential, nor indeed the hype.
He was in danger of a being dismissed as a show pony – someone who could do it when the attention was there, but not across the hidden demands of a week-to-week, midweek-to-midweek, season.
There are, of course, a number of factors behind the struggles, not least the club's managerial merry-go-round over recent years and Cardiff's lack of playing identity.
The contrast this season under a head coach who has successfully and swiftly implemented his methods since leaving his role with Manchester City's youth academy has been stark, though.
Already in 2025-26, Colwill, admittedly at a lower level in the football pyramid, has bagged four goals and registered five assists across all competitions, a drastic improvement on his previous numbers.
His influence has been clear for all to see - with former boss Neil Warnock even hailing him as the club's Gazza (Paul Gascoigne).
Indeed, according to Sofascore, Colwill has created five big chances in the league so far this season, with Joel Bagan (six) being the only Cardiff player to manage more.
His average of 1.9 key passes per match is the best of any Cardiff player while his average of 1.4 successful dribbles per game also puts him at the top of the pile in that category within the Bluebirds' ranks.
His form didn't go unnoticed at international level, either, as he has been a more regular figure in the Wales fold once again - finally making his first appearance under Craig Bellamy in Wales' sketchy 1-0 World Cup qualifying win against minnows Liechtenstein in Vaduz earlier this month.
A scan has now determined the extent of the 23-year-old's injury, although, as Barry-Murphy clearly stated, the expectation is that the playmaker may yet benefit from stint on the sidelines.
David Turnbull, Colwill's replacement at Northampton, has been in and out of the starting line-up in League One this season but may be the man to benefit from his team-mate's injury, with Chris Willock also back in the fold following a short spell out due to a thigh issue.
But in the short-term, the coaching staff at both Cardiff and Wales will be hoping Colwill shows his powers of recovery – as will fans of club and country.
If 2025 was a breakthrough year for Colwill, then 2026 – when fit – could be even better.
