Ioane became the All Blacks' first-choice winger after he supplanted Julian Savea ahead of last year's British and Irish Lions series and has amassed 22 tries in 21 tests.
Injuries to the Blues' playing stocks this season, however, forced Umaga to select him in the midfield for several games.
While the 21-year-old said several times over the last two years that he saw his long-term future in the midfield and that he "enjoyed everything about centre", Umaga said that he would remain on the wing next season.
"He's the world's best wing," Umaga said after naming next season's Super Rugby squad.
"We have committed to Rieko about him playing on the wing and that's what will happen," added the former All Blacks captain, who also started his international career on the wing before making the transition to midfield.
Umaga added the desire to retain Ioane on the flank had led to the recruitment of his former Wellington Hurricanes and All Blacks midfield partner Ma'a Nonu from Toulon for the 2019 season.
The 103-test cap inside centre would provide some stability in the midfield for the Blues, who had to resort to using Ioane as a stop-gap measure this year with two-times World Cup winner Sonny Bill Williams injured for much of the 2018 season.
"We are a better side when we have experience on the field," Umaga added. "We know we have to manage our All Blacks, and Sonny is part of that, and is one of the reasons why Ma'a has come on board."
The Blues have been the worst-performed New Zealand Super Rugby side for the last four years and Umaga added the duo would be expected to mentor the younger players, such as Levi Aumua, Tanielu Tele'a and Auckland provincial captain TJ Faiane.
"Between the two of them they have that experience," said Umaga of Williams and Nonu's combined 153 test caps and more than 200 Super Rugby games.
"We want to bring on some of these young guys to take that experience onboard themselves for the future of the Blues. We are expecting these guys to learn from them... and that's exciting."