German defender Marvin Compper is poised to become Celtic's first signing of the January transfer window after the Parkhead club gave him a VIP tour of their facilities.

Sportsmail can reveal that the 32-year-old made a cloak-and-dagger trip by private jet from Leipzig to Glasgow on Thursday.

The former Germany international was offered a tour of Celtic Park before flying home after talks.

RB Leipzig centre half Marvin Compper is at the top of Brendan Rodgers' January wishlist

Compper played for RB Leipzig in last week's Champions League loss to Besiktas, but has otherwise drifted out of the picture at the club currently lying second in the Bundesliga and failed to make the squad for Tuesday's draw with Wolfsburg.

Celtic are expected pay £900,000 to secure one of the two central defenders manager Brendan Rodgers hopes to sign in the January transfer window.

Admitting there is room for improvement on the defensive front, the Celtic boss said on Friday: 'Our identity as a team is to defend well first of all.

Celtic boss Rodgers wants to strengthen his side particularly in central defence

'And I think we can still be better on that front even though we've conceded less goals at this period of the season than we did last season.'

The champions travel to Tynecastle to face Hearts on Sunday when they will be looking to extend their unbeaten run in domestic football to 70 games.