Roy Keane has lost the faithful friend who brought him through the Saipan row with Mick McCarthy and some of the most stressful incidents of his career.
Keane is said to be "inconsolable" over the death of Triggs -- the golden labrador he once claimed to trust more than his Manchester United team-mates.
The nine-year-old dog, who had become a household name and even had a Facebook profile dedicated to him, lost his battle with cancer.
"It's fair to say Triggs has been a calming influence on him over the years so this sad news will have the Ipswich Town players panicking," said a source.
Triggs became a celebrity after the Saipan row in 2002 when Keane quit the Ireland team after a row with McCarthy.
The dog was photographed daily on walks with his master after Keane was sent home from the World Cup.
He was subsequently regularly seen on these walks during all the stressful periods in the footballer's career.
Triggs even adopted some of his master's fiery traits and became the centre of a police probe last year when his behaviour sparked angry words between his owner and a neighbour.
When Keane quit as Sunderland manager two years ago, it prompted the joking comment that Triggs would have to prepare for hours of walking.
When he became Ipswich Town manager, Keane joined in the joke saying: "I decided that Triggs needed a break."
The dog even starred in an ad for the Irish Guide Dogs last year.