Celtic have paraded Stephen Pearson as their new signing.
Pearson could make his debut against Ross County
Motherwell "very reluctantly" accepted a £350,000 fee for the Scotland midfielder Stephen Pearson on Wednesday after protracted negotiations.
The 21-year-old signed a four-and-a-half year deal worth £2m and could make his debut against Ross County.
He told BBC Sport on Wednesday: "I have obviously supported them all my life. My heart has always been set on Celtic, so it is a dream move for me."
Pearson passed a medical on Friday but had already enjoyed a champagne celebration with his family at the conclusion of a week of negotiations between the clubs.
"It had dragged on a bit, so I am very relieved as I did not want to leave on a pre-contract agreement," he said. "I wanted Motherwell to get as much money as possible.
"Now I can concentrate on my football as I know that Celtic have a team full of world-class players and I might have to bide my time before breaking into the first team."
There had been interest from Blackburn Rovers and Everton, who had signed Pearson's former Well team-mate, James McFadden, earlier in the season.
But, despite McFadden singing the praises of the English Premiership, that was never really a possibility as to sign for Celtic was "a dream came true" for Pearson.
The Scottish champions elect were the only realistic bidders and had warned Well that they would sign a pre-contract agreement with the player on Thursday if their latest offer was not accepted.
But more negotiations followed, with Motherwell dropping their insistence that they would receive a percentage of any future transfer fee.
Motherwell stressed in a statement that they and manager Terry Butcher had made strenuous efforts to retain Pearson at Fir Park but finally agreed to the transfer, believing the player had "emotionally and contractually" left the club.
"We have very reluctantly accepted an offer of £350,000, " said chairman Bill Dickie.
"Initially, Celtic offered £250,000, but that was wholly unacceptable.
"Although the offer was increased, we still feel it is substantially below the true value of the player and we were perfectly prepared to leave the matter to a tribunal.
"However, after extensive discussions with Terry Butcher, it became clear he did not have any confidence in Stephen Pearson being ready and willing to meet the challenges that will lie ahead at Fir Park until the end of the season.
"In view of that, it was agreed it was in the best interests of Motherwell to sell the player to Celtic."