Left-back Boli Bolingoli-Mbombo has completed his move to Celtic from Rapid Vienna, saying he only learned of the Scottish champions' interest last week.
The 24-year-old has signed a four-year contract after the clubs agreed a reported £3m transfer fee.
Belgian Bolingoli-Mbombo stressed that he views himself as "a left full-back" - a position currently occupied by Kieran Tierney.
The 21-year-old Scotland cap has been the subject of a bid from Arsenal.
However, in announcing the signing of Bolingoli-Mbombo, Celtic stressed that he "can play in a variety of left-sided roles", while manager Neil Lennon previously said he "gives us competition at left-back".
Bolingoli-Mbombo - a cousin of Belgium internationals Romelu and Jordan Lukaku - hopes the move to Glasgow will boost his chances of earning a first cap for his country.
"My little brother is also playing in Belgium, it is in our family's blood, and hopefully one day we'll be playing together in the national team of Belgium," he said.
Bolingoli-Mbombo played his first match for Rapid in a friendly against Celtic two years ago on his birthday - and his move comes two days after he turned 24.
"It is a little late but a nice birthday present," he said. "I heard about it first last week when they had contact with my agent and directly I said yes - you can't say no to a club like Celtic.
"It is a great opportunity for me to make the next step in my career."
Bolingoli-Mbombo, who joined Rapid from Club Brugge, played 32 times last term for the side who finished seventh in the Austrian Bundesliga, including twice against Rangers in the Europa League.
Now the player described by Lennon as "strong, athletic and good on the ball" hopes to prevent the Ibrox side denying Celtic a ninth title in a row after swapping one green and white strip for another.
"Hopefully we can win some more titles because I know this club want to break some records," he added.
Find all the latest football transfers on our dedicated page.