Scarlets attack coach Mark Jones, the former Wales wing, has left the region with immediate effect.
Jones was due to be replaced in their set-up by ex-team-mate Stephen Jones before the 2015-16 season.
But he is to depart with Wayne Pivac's side lying eighth in the Pro12 table and battling to qualify for next season's European Champions Cup.
"It is time to move on now," said Jones, citing a difference in rugby philosophy.
"It's the right decision for the region and allows me to spend some quality time with my family and embark on the next chapter in my career.
"The Scarlets are developing a new direction and philosophy within the coaching and playing group which differs from my own and we all agree it makes sense that the coaching group are allowed to pursue this new direction without me.
"I leave with fond memories and grateful for all the opportunities I have been given."
Jones was forced to retire by injury in 2010 and joined the region's coaching staff.
The 35-year-old made a combined total of 163 appearances for Llanelli RFC and Scarlets after joining them in 1997.
Jones made his Wales debut against England in 2001, four years after leaving home club Builth Wells for Stradey Park and went on to captain them in his final playing season, 2009-10.
Scarlets have won five of their 13 Pro12 games this season, drawing twice and losing six times.