The 39-year-old admitted to robbing both a KFC restaurant and Tesco Express store in October last year and was sentenced today at Bolton Crown Court.
Alker and his co-defendant Michael Naylor, who received the same sentence, were wearing balaclavas when they raided the KFC in Pemberton armed with a machete.
The pair then moved on and took a bundle of GPS tracked £20 notes from the Tesco store in Whelley, with police tracking them down to Delegarte Street in Ince.
A spokesperson said that Naylor was found hiding behind a car before Alker came out from behind some nearby bushes with his hands up.
Wigan-born Alker spent his entire career at Salford, making his professional debut in 1997 at the age of 18.
Just three years later he captained the Reds for the first time and after promotion to Super League, he quickly became one of the best English hookers in the game.
This was recognised in 2002 when he was called up to play for Lancashire and in 2005, Alker made two appearances for his country.
In August 2010, he retired from rugby league due to injury after 13 years at Salford and well over 350 appearances for the club.
Alker took up a coaching role with the Reds following his retirement and in 2011 he was the assistant coach to Shaun McRae.
However, things ended on a sour note with the Reds when he was dismissed from the club's coaching team in April 2012 after being sent home from a training session.
He later filed a complaint against the club feeling he had been 'ousted' from his job after a disagreement with the hierarchy of the club.
Alker attracted the support of the entire rugby league family when he was reported missing in April 2016.
He was found safe and well the following day after numerous pleas for help and information on social media.