Sellars, who made over 500 appearances during his career including spells at Leeds United, Newcastle United and Blackburn Rovers, was involved in the accident following a trip to a football training camp in Dubai.
Nottingham Crown Court heard the 47-year-old went straight to work at Manchester City, where he is youth team coach, after returning on an overnight flight from the Middle East, before setting off for home in his BMW.
Jonathan Straw, prosecuting, said Sellars stopped for a coffee - but it wasn’t enough to prevent him dropping off while travelling along the A6 at Furness Vale in Derbyshire.
He collided with Simon Burnett, who was riding a Yamaha motorcycle, at around 2.30pm on April 11 2011.
Mr Burnett, 47, was airlifted to hospital but died of his injuries later that day.
Sellars pleaded guilty to causing death by careless driving, and he was handed a six-month suspended sentence and ordered to do 300 hours of unpaid work in the community.
He was also banned from the road for two years.
Recorder Shaun Smith QC, sentencing, said Sellars wasn’t showing off or speeding, but had caused the death of Mr Burnett in a single careless act.
Afterwards Sgt Forbes Marshall, of Derbyshire Police, said: “This case brings into stark clarity just how dangerous it can be when you drive when you are tired.”
The court was told the family of Mr Burnett had received a personal apology from Sellars, who lives in Derbyshire.
Sellars began his career in 1983 and played for eight clubs before retiring in 2003.
He is currently coach of the Manchester City U18 team.