According to The Mirror, Zaha accused Morrison of ball hogging, to which the West Ham United attacker responded by criticising his teammate's performance.
Norwich City winger Nathan Redmond stepped in to intervene when Morrison raised his hands, but the same newspaper reports that the arguing continued in the tunnel, with claims that Morrison said: "Me and you will have it out."
However, Southgate has said that the pair have put their differences behind them ahead of this evening's vital European Championship qualifier at stadium:mk.
"There are no issues," the 43-year-old is quotes as saying. "I spoke to them and the lads when we got into the dressing room, and before they left the ground they were hugging.
"I think we have to have an appreciation of each others' characters. We're a strong team because we've got that diversity of character, we respond in different ways.
"Those two are the types of players they are because they live slightly on the edge in terms of their responses and emotions. We have to understand as a group that we need all of those types of people to be a successful team. Those guys will win us matches."
England take on San Marino at Greenhous Meadow Stadium on Tuesday.