The 26-year-old lasted just 60 minutes into his eagerly anticipated comeback game as the Scarlets were beaten by Edinburgh 21-15 in their first Celtic League fixture. Jones had not played since picking up a groin injury in the 11-9 Six Nations win over England in February.
And the heartbreak of missing the remainder of Wales's famous Grand Slam has been compounded by the news that he will now miss the autumn internationals. Despite having an operation on Tuesday, Jones will not have recovered in time to face New Zealand, South Africa, Australia and Fiji later this year.
"It's hugely disappointing for us but more importantly it's a devastation as far as Daf is concerned," said Scarlets director of rugby Gareth Jenkins. "It was a big comeback this season for him, something he's really been looking forward to having missed most of last season and the celebrations that went with the RBS Six Nations win.
"He took a knock which resulted in a ligament snapping in his finger which then detracted into his arm. There was no alternative really - it was either losing the use of that finger or having surgery to bring the ligament back into the finger and repairing it."
Wales Under 20 travel to Newcastle on Friday to face England at Kingston Park. With the likes of Jack Dixon and Ashley Evans returning to the squad, it's arguably the strongest side head coach Byron Hayward has put out in the tournament so far. WRU TV previews the game with Defence Coach Richard Hodges and captain Steffan Hughes.
Wales head coach Warren Gatland gives an exclusive interview to WRU TV after naming his side to face England in the RBS 6 Nations at Twickenham on Sunday. Gatland has recalled British & Irish Lions duo Jonathan Davies and Alun Wyn Jones to his side while Rhys Webb retains his place at scrum half.
Scrum half Rhys Webb and lock Jake Ball both made their first Wales starts in last Friday's win over France at the Millennium Stadium. They talk exclusively to WRU TV's Luke Broadley about their experiences of the day.
Wales Women's Head Coach Rhys Edwards has made three changes to his side to face France at Aberavon on Sunday, where he expects his side to be given a tough time against one of the best teams in the world.