Gerry Armstrong has quit his position as assistant to Northern Ireland football manager Lawrie Sanchez.
Gerry Armstrong was a World Cup hero for NI in 1982
Armstrong cited business commitments and personal reasons for his decision to step down before the start of the European Championship qualifiers.
"I could not give Lawrie the commitment required for the entire programme," said Armstrong, whose wife Debby is expecting a baby.
Sanchez thanked Armstrong for his "huge contribution to the squad".
"He has helped us in raising the expectations of supporters and improving the performances on the field and I thank him for those efforts," said the Northern Ireland manager.
"I would also like to wish him and Debby all the best for their new arrival and good luck for the future."
Armstrong took the Northern Ireland role shortly after Sanchez's appointment in January 2004.
The former Tottenham Hotspur striker also works as a TV football pundit.