Celtic would be signing a player of "some pedigree" if they complete a deal for Marvin Compper, according to German football journalist Raphael Honigstein.
Compper has played only twice for RB Leipzig this season, due to the form of the club's younger players.
"Marvin Compper is one of those centre-backs you don't see a lot during the game, he tends to solve problems before they arrive," Honigstein said.
"He's not one for thunderous tackles, but smart positioning."
Compper flew into Scotland on Tuesday ahead of his expected move to Celtic Park, subject to successfully completing a medical.
He was a key figure for Leipzig as they earned promotion to the Bundesliga in 2016, and then qualified for the Champions League in their first season in the top flight.
"Leipzig have had a very strong policy of not signing anyone over 25 but they made a huge exception for him because [Leipzig director of sport] Ralf Rangnick believed his experience was necessary to take them up to the Bundesliga," said Honigstein, who is a regular pundit on Five Live's Euro Leagues Football Show.
"He was brought up on Ralf Rangnick football at Hoffenheim, so very quick transitions, he's used to the players in front of him pressing and quick, vertical football, but also opposition teams sending balls over the top, he's very good at being in the right space and dealing with these situations.
"Dayot Upamecano [Leipzig defender] has been fantastic since coming up, Ralf Rangnick keeps saying he should be in the French national team.
"[Compper] has just lost his position to younger, more agile players. Even the captain [Willi Orban] has found himself on the sidelines because Ibrahima Konate and Upamecano have struck up such a good partnership.
"He's at an age where he doesn't get any benefit from sitting on the bench, so I can understand why he's taking the opportunity to be a starter in a team that's going to win titles."
Celtic have moved swiftly to try to sign Compper - who has a contract at Leipzig until 2019. One season at Fiorentina apart, the defender has spent his entire career in Germany, but Honigstein says a move abroad makes sense at this time in his career.
"I don't think there were other clubs chasing his signature, but Bundesliga clubs are very reluctant to make big moves in the winter, they prefer to move early in March and August for summer signings," he said.
"The number of clubs who want an experienced, ready-made centre-back who doesn't represent a lot of value going forward as an asset is limited.
"But his football education is very much about being very quick, very technical, trying to look out for that forward ball all the time."