If they do want to sell for cheap then there's a reason. Look at Holding.

Great player and a brilliant fit for the system, but his injury record is a big concern.

I'd imagine that's a big part of why Arsenal are moving him on, moreso than ability or performances.

I tend to agree - injuries are the concern. Frankly, should be a lot less than 20 mil. Isn't Lewis-Hall around 20 mil? Tierney is probably the better player but isn't worth anything at all if injured all the time. Lewis-Hall is probably already good enough for us but could get better. I wouldn't really see Tierney as improving - more unfortunately he's usually recovering from his last serious injury. I can't remember what his original issue was - something like hip or back.
Then again, he has a more favourable injury record than a couple of players we have signed already.
Maybe he could come in cheap, be injury free and be excellent but that seems more hope than expectation.

I tend to agree - injuries are the concern. Frankly, should be a lot less than 20 mil. Isn't Lewis-Hall around 20 mil? Tierney is probably the better player but isn't worth anything at all if injured all the time. Lewis-Hall is probably already good enough for us but could get better. I wouldn't really see Tierney as improving - more unfortunately he's usually recovering from his last serious injury. I can't remember what his original issue was - something like hip or back.
Then again, he has a more favourable injury record than a couple of players we have signed already.

Maybe he could come in cheap, be injury free and be excellent but that seems more hope than expectation.

Absolutely.

Also there are rumours we are still after Lewis Hall - a better long term option IMO.