But Brown believes everyone should wish the Scotland worldwide well in the Premier League.
"He got a fantastic move and he's got a fantastic club as well".
"In the last ten minutes of the first half and the first ten or 15 of the second it was an even game and we were looking at making changes to give us the best chance to get that equalising goal". They can come back as well, that's what this club is all about, he said.
Tierney returned to Celtic's Lennoxtown training ground on Sunday to say goodbye to his team-mates, something which was welcomed by manager Neil Lennon.
With Championship sides now not able to bring in any more players it is yet to be seen if Phillip Cocu is willing to let Lowe leave without being able to replace him. He got a nice farewell from the players.
According to the Scottish Sun, Russian side Zenit Saint Petersburg are readying a £12m bid for the player and also want to pay him handsomely too.
Lennon is still to iron out with chief executive Peter Lawwell and recruitment staff exactly how they will go about the final weeks of the transfer window following the £25million windfall.
The head coach said: "They moved the ball quicker than us, they pressed it better than us, these are things we can do. I imagine we may not spend all of the money but we will spend some of it, I'm sure".