Brazilian forward Douglas, whose 21 goals in 2015 were second in the J. League first division, will leave league champion Sanfrecce Hiroshima.
The club announced the move, along with the acquisition of Nigerian striker Utaka, on Tuesday.
Douglas had been on loan with Hiroshima from J2 side Tokushima Vortis. According to a club source, Sanfrecce had hoped to extend his loan period or acquire the marksman on a full transfer, but were unable to meet Vortis' terms.
It appears likely that Douglas, who played 4½ seasons for Tokushima and had a short loan spell with Kyoto Sanga in 2014, will play this year for a club in the United Arab Emirates.
The 28-year-old striker contributed to Sanfrecce's third-place finish in last month's Club World Cup, but the team source said losing such a valuable player was business as usual for the three-time J. League champions.
"It's almost an annual thing, losing players," the source said. "New players come in and then we need to develop a new style."
The 31-year-old Utaka, a former Nigeria international who scored nine goals in 28 games last season for Shimizu S-Pulse, will be on loan with Hiroshima through January 2017.
Utaka has also played in the Danish and Chinese leagues.