"Yes, he will (open), with Jonny (Bairstow)," Morgan confirmed as quoted by Sky Sports ahead of the opening T20I on Friday.
"Like I've said before, we will continue with this until we feel the need that it's not working.
"We feel that Jason (Roy), Jonny and Jos are three of our greatest-ever white-ball players - unbelievable strikers of the ball, batsmen you do not want to bowl against - so if one out of the three of them gets going past the first six overs of the powerplay and into the middle overs, it puts us in a really strong position for the last 14.
"We always pose the question of, 'how do we get the best out of all of our players?', and when you talk about those three guys specifically, it's more obvious with Jonny and Jason batting at the top of the order.
"But, trying to get the best out of Jos, at the moment we feel the more balls he faces, the more influence he can have on the game.
"If it gets to fine-tuning things down the line and that hasn't necessarily worked out, we can always fall back on Jos in the middle order," he added.
Check Eng vs Aus 1st T20 playing 11 prediction and Southampton weather forecast here
The England captain further said Aussies will have a slight edge over them as the No. 1 T20 side have the firepower to beat the 50-over World champions.
England are not quite a full strength, with Jason Roy injured and Ben Stokes still unavailable for family reasons as his father battles brain cancer.
"Probably Australia," he said when asked which team holds the edge. "They have their strongest squad here, so will probably be putting out their best XI. So, if you're to go on that, I'd say they're just favourites.
"For the first time this summer we are seeing the majority of our best team on the park and that's great.
Check England vs Australia latest cricket news here
"Bar injury and absent players, which is only a couple, we are at full strength and that is a nice place to be every now and then.
"We don't have to pick our best XI every series that we play because we can't put all our eggs in one basket. We need 16 or 17 players in the lead up to World Cup selection all vying for selection in the best 15," he added.
Business Standard has always strived hard to provide up-to-date information and commentary on developments that are of interest to you and have wider political and economic implications for the country and the world. Your encouragement and constant feedback on how to improve our offering have only made our resolve and commitment to these ideals stronger. Even during these difficult times arising out of Covid-19, we continue to remain committed to keeping you informed and updated with credible news, authoritative views and incisive commentary on topical issues of relevance.
We, however, have a request.
As we battle the economic impact of the pandemic, we need your support even more, so that we can continue to offer you more quality content. Our subscription model has seen an encouraging response from many of you, who have subscribed to our online content. More subscription to our online content can only help us achieve the goals of offering you even better and more relevant content. We believe in free, fair and credible journalism. Your support through more subscriptions can help us practise the journalism to which we are committed.
Support quality journalism and subscribe to Business Standard.