Sakala has put pen to paper on a pre-contract agreement with the Scottish giants and will join them on a four-year deal in the summer.
The hitman is set to share the dressing room at Ibrox with Rangers stars Hagi and Roofe, having previously played against the duo when they were plying their trade in Belgium for Genk and Anderlecht, respectively.
Sakala has revealed it has always been his dream to play with great players like Roofe and Hagi and stressed he is aware of their quality having squared off against them in Belgium.
The 24-year-old is confident he will learn a lot from the Gers duo from next season onwards as he gears up to take the next big step in his career.
Asked how excited he is to play with Roofe and Hagi at Rangers having squared off against the duo in the Belgian league, Sakala told Rangers TV: “Yes, it has always been a dream to play with great players like Roofe and Hagi.
“I played [against] them here and they are fantastic players, very good players.
“So, I know that I will learn a lot from them.
“I am looking forward to meeting them and to start working with them.”
Sakala has 13 goals to his name for Oostende in the Belgian top flight this season and now will be aiming to add more to his tally in Gers colours next term.