Kristoffer Ajer has completed a medical with Brentford ahead of his £13.5million transfer from Celtic.
The newly-promoted side are keen to add a centre back to their ranks before the top-flight campaign gets underway and have been in talks over Ajer in recent days.
The Norwegian went public with his desire to leave Celtic at the start of last month and he had attracted interest from the likes of Newcastle, Norwich City and Bayer Leverkusen.
Celtic rejected a £10m bid from Norwich but are now poised to bank a sizeable sum for a player in the final year of his contract.
It is thought a deal for the 23-year-old has been agreed and will be formally announced when the final details have been ironed out.
The Scottish giants drew 1-1 with Brentford's sister club FC Midtjylland on Tuesday night in a Champions League qualifier but Ajer was not involved.
Brentford have also confirmed the signing of midfielder Frank Onyeka on a five-year deal from Midtjylland.
The Nigerian was the club's first signing of the summer and penned a five-year contract after being granted a work permit.
He must now undergo a period of isolation before he can begin training with his new team-mates ahead of their Premier League opener with Arsenal on August 13.
Brentford's preparations continued on Tuesday night with a 2-0 friendly win over Boreham Wood.
Ivan Toney and Tariqe Fosu found the back of the net in either half in what proved to be a comfortable win at Meadow Park.