In honesty, the only real appeal Celtic have (unless you're a fan of theirs) is that they pay "decent" money relatively speaking for the Scottish league and they offer the opportunity to be routinely humiliated in European competition. If getting bodied 5-0 and 7-1 by PSG and 7-0 by Barcelona is your thing then it's the ideal place for a player.
It's a "big" club absolutely but it's very much a platform to the Premier League now eg: Armstrong, VVD, Wanyama etc. If a player up here gets the chance to go direct to PL or Championship then why bother with that middle-step eg: Robertson.
Turnbull is very publicly a Motherwell fan. It's difficult for fans of Rangers and Celtic up here to comprehend that but he's been very vocal about Motherwell being the club he supports.
He's also a pretty switched on kid. There was interest from England (and possibly actual offers) at the turn of the year but he signed an extension with Motherwell because he wasn't convinced he wouldn't just get dumped into the u23s (Swansea and Southampton were being quoted with interest):
“There was interest from other clubs but it was always my intention to stay here. It was just about getting the
right contract.
“The most important thing was getting more experience. I need that game time.
“English clubs were looking at me but I could go there and find myself sitting on the bench or playing U23 football so this is the right place for me."
Link
I'd guess that his 2nd half of the season and Football Writers YPOTY win and PFA YPOTY nomination will give him a bit better leverage in that conversation now.
Fact is there's an increasing number of Scottish "talent" whose first choice is a move down to England as - to be crass about things - your league pays far better wages.
The example of the problem Celtic have at the moment is what happened with John McGinn last summer. There was a deal to be done, Rodgers wanted the player, Celtic had the money to pay for him: Hibs were asking around £4m but Celtic - being Celtic - continually low-balled (because it's what they do) on the assumption that Hibs would 'cave' and they'd get him on the cheap (around £1.5m I think).
In the end Villa came along and dropped a good deal that Hibs were happy to take and the player doubled the wages Celtic were offering. Hibs will now presumably coin it in if/when he moves on. Rodgers spat the dummy that he didn't get the player and bolted to Leicester as quickly as he could.
I'd guess that there's an element of "you can't lose if you don't play the game" around the reports Celtic seem to have fed that they won't get dragged into a "bidding war" re: Turnbull (that story is in the Scottish Sun if you want to read it but I won't link to it). The irony of course is that they're currently "bracing" themselves for a "bidding war" over Oliver Ntcham ¯\_(ツ)_/¯.
If a club like yourselves (or any PL or Championship side) are genuinely interested in Turnbull then you're in a better position to pay a fee Motherwell will accept (the vast majority of Motherwell's transfer business is cross border btw they rarely sell to Rangers or Celtic) and offer a more attractive wage for the player.
Again, for what it's worth all the noises that have been coming out of Motherwell have been talking about Turnbull in relation to England.
It's a bit of a stretch but here's our (excellent) CEO Alan Burrows talking about Turnbull as a potential EPL player (his assessment in his original Tweet about Turnbull being a Rolls Royce of a player is spot on too).
