Kamau, who scored the opening goal in Sunday’s 3-1 grand final win over Western Sydney, will link with the club until the end of the 2017-18 season and add depth to Victorian club’s forward line.

With 29 matches to his name, including 18 in the most recent season, City coach John van’t Schip said he expected the 21-year-old to grow even more at the club.

“He is still young, has shown positive signs and he is a player we see as having great potential for further development with us,” van’t Schip said.

Kenyan-born Kamau arrived in Australia at age four, before playing for a number of junior clubs in Adelaide before joining Adelaide’s youth team in 2013.

He has scored three goals in the 2015-16 season.

“Adelaide United and its coaching staff would like it to be known it was always the club’s intention to keep Kamau, considering he is a local South Australian and considering his development was through Adelaide United’s setup,” the club said in a statement on Thursday.

“However Kamau, his family and management believe its best for him to continue his career elsewhere.”

United are also braced to lose winger Craig Goodwin to Sparta Rotterdam.

Goodwin, who on Wednesday night won the club’s player of the year award, has reportedly signed a deal to join the Dutch club.

But a club a official said there was no official announcement yet on the Goodwin’s future.

Meanwhile, Adelaide’s on-loan striker Eli Babalj will return to his parent club AZ Alkmaar in the Eredivisie.

Babalj made eight appearances for the Reds but ruptured an anterior cruciate ligament in round 16 and will continue his rehabilitation in Europe.

-AAP