Szabolcs Huszti's agent says the Hungarian would have been willing to join Celtic, if the SPL champions had not wanted to wait until the summer.
The Hungarian playmaker signed for Zenit St Petersburg before the close of the transfer window as a replacement for the Arsenal-bound Andrey Arshavin.
Hamburg had also been keen to capture Huszti, while Celtic were hoping to sign him on a free transfer when his contract at Hannover expired in the summer.
Huszti's representative Vladan Filipovic was expecting an offer from the Bhoys, but the player is now happy to have agreed a deal with Uefa Cup holders Zenit.
"I expected an offer from Celtic and I can say they were interested," said Filipovic in the Daily Record.
"I spoke with (chief executive) Peter Lawwell and they were correct in their negotiations. But like a few others they wanted to sign him on a pre-contract.
"Hamburg and Zenit wanted him now and the most important thing is Zenit bought him.
"That says everything about how they wanted him because he had only six months of his contract to run and they paid.
"I was in Glasgow one time to speak with Celtic about Szabolcs and he knew everything that was going on and that Hannover would sell if they got good money.
"Szabolcs would have come to Celtic, but they wanted to wait until the summer.
"It was a last-minute decision by Zenit and we signed on Sunday so he could make their list for the Uefa Cup.
"Szabolcs is happy because Zenit are a big club and St Petersburg is a nice city."