Eoin Morgan says Alex Hales could still make an England comeback, but it will take time to repair a "breakdown in trust" with the team.

Hales was dropped last year, a month before England's triumphant Cricket World Cup campaign on home soil, after he was reportedly handed a 21-day ban for what was described as an "off-field incident".

The batsman has not played for his country since but has been in sparkling form with the bat for Sydney Thunder in the Big Bash League in Australia.

Morgan stated that Hales' international career may not be over just yet, with the T20 World Cup coming up in Australia this year, but the England captain indicated that it may be a while before the 31-year-old is considered.

Asked if Hales could make an international return, he told Sky Sports: "Yes, absolutely.

"Alex is in fantastic form for Sydney Thunder at the moment but his form has never been a question about him coming back into the squad

"What happened prior to the World Cup last summer was a complete breakdown in trust between Alex and the team.

"The way back in for Alex is to try and rebuild that trust and that takes a considerable amount of time. We are in that time at the moment."

Meanwhile, Tom Banton, Saqib Mahmood and Matt Parkinson could make their ODI debuts in the first game of the three-match series against South Africa on Tuesday.

With Jos Buttler and Ben Stokes rested, Morgan says those who are given a chance against the Proteas must grasp it with both hands. 

"I think we use ODIs as a great opportunity to build strength in depth throughout our squad," said Morgan.

"This series, as a starting point, will see guys come in and make their debuts and give people opportunities to stake a claim for positions that have been cemented for some time now.

"One of our strengths going into the last World Cup was competition for places and guys in those positions becoming not just very good England players but world-class international players."