The Republic of Ireland legend feels the Spaniard could replace the newly-appointed Everton boss at Southampton.
The Spaniard was fired by the Toffees in May following a second successive 11th-placed finish in the Premier League which, given their squad, is perhaps a serious underachievement.
Former Ajax boss Frank de Boer - who was also linked with the Everton role - is said to be among the frontrunners to replace his compatriot on the South Coast, but McGrath feels that Martinez should apply for the role.
The Aston Villa legend took to Twitter to share his views on the matter.
Footballs getting so strange these days , Why doesn't Roberto Martinez apply for the Southampton job ! #Thisisnotajoke !— Paul McGrath (@Paulmcgrath5) June 14, 2016
Martinez, in his defence, is still a good manager. He has an FA Cup title with Wigan Athletic under his belt already and, at 42, he is certain to improve in the coming years.
Despite his Everton struggles, the future is bright for the Spaniard, but Southampton may want a bigger name to replace the Dutchman.