Celtic's transfer business has picked up some pace in recent days. They have managed to get a club-record deal for Kasper Hogh over the line, something that not many fans would have expected to happen even a week back.

The move has been made official. It is believed to have taken a transfer package north of £11 million to make it happen. Fans will be hoping that Hogh delivers on the expectations.

Of course, Celtic have signed another striker this summer in the form of Camilo Duran. He has looked very promising in pre-season as well, scoring three goals in three outings. Expect him to start up front on Flag Day.

At the same time, some moves are being worked on as well. Names like Haissem Hassan and Mika Baur have been doing the rounds for a while. Will they happen or collapse? That is unclear at this point.

On the other hand, it looks like Celtic have made a move for one of their former players, although it might not be on the cards.

According to a report from Richmond and Twickenham Times, Brentford rejected an approach from Celtic to sign centre-back Benjamin Arthur on a permanent deal.

Brentford rate Arthur very highly and consider him part of the club's future plans. As a result, they turned down Celtic's approach immediately.

Arthur spent the previous season on loan at Celtic. And interestingly, he did not get too many chances under Martin O'Neill.

He only made six appearances, having arrived on loan from Brentford in the middle of the season. And although he did impress many with his game in those limited appearances, one would imagine that the youngster would have come in hoping for a lot more game time.

Consequently, not many would have expected to see Celtic try and sign him on a permanent basis this summer after the bit-part role he had. So, this approach would have come as a surprise.

It remains to be seen whether Celtic end up making another move to sign Arthur or not. For now, it seems off the table.

It does go to show that Celtic have their eyes on strengthening their centre-back ranks further this summer, which is a positive sign.

READ MORE: Celtic Transfer Collapse Fears as Record Bid Rejected

Celtic do have three quality options in defence in the form of Liam Scales, Auston Trusty and Cameron Carter-Vickers. All of three of them have proven themselves as starters for the club.

Carter-Vickers has dealt with far too many injury problems over the last few years, though. One has to wonder if we will ever see him back at his best again.