Partick Thistle manager Alan Archibald admits the imminent departure of Liam Lindsay will be a bittersweet moment for him.

Lindsay, who turned down a move to English League One side Oxford United at the weekend, is set to sign a deal with Championship side Barnsley after a fee between the clubs was agreed. Reports in Yorkshire suggest Thistle could bank around £350,000 for the talented defender.

Lindsay, 21, was a key figure in Thistle’s rise into the top-six of the Ladbrokes Premiership last season. Despite the disappointment of losing one of his brightest talents, Archibald has given Lindsay his blessing as the promising centre-half takes the next step in his burgeoning career.

Archibald, who is still looking to bring the on-loan Niall Keown back to Firhill, said: “I’ve known Liam since he was 16. I brought him into the Under-17s and I take great pleasure if he does move on and becomes a better player. You just like seeing good young players doing well.

“At 16 he had the raw materials and he’s something of a dying breed in Scottish football in that he’s a big honest centre-half who wins headers and tackles. If it goes through then it’s a good move for him.

“I didn’t think League One was right for him and I don’t mean any disrespect to Oxford.

“He’ll be under pressure to build on this year and he’ll be in the spotlight in a Championship side. It’s the next step in his career. I just think in terms of trying to get into the Scotland squad then you need to be in the Championship to be near that. Unless you are there then I think the international manager might not look at you.

“Another 40 games here - if he was to stay - would not harm him. I think he’s a better player for having played so many games for us.

“Whether he’s here or there then it’s all about him raising the bar and the level of performance. We are the kind of club who develops players and lets them move. It’s always sore though when one of your best players leaves. But he’s improved and it gives you pleasure seeing him come on.”

Archibald has already added Blair Spittal to his squad ahead of the new campaign but the Thistle boss admits replacing Lindsay will cause him some headaches.

He added: “It’s a huge problem, he’s one of our best players and he’s a left sided centre-half which is also hard to get. When you are used to playing with a left and a right then it’s an added bonus. Most teams have two right-sided centre-halves

“It gives us massive problems but we do have targets out there and the good thing is that it’s happened early. That was always my conversation with the board. If we are going to lose him, let’s lose him early so that we have a couple of months to replace him.

“We always said we were looking to bring in four or five players. We’ve got most of the boys tied up. We did our business early so hopefully we don’t lose any more and we’re only looking at those four or five players so we can build on what we’ve got.

“Without a doubt it will be harder to stay in the top six. Most seasons it goes on budget in terms of where teams finish.

‘You’ll get the odd surprise but there are five big budgets in the league now with Hibernian back up there.”

Thistle’s players reported back for pre-season training yesterday and Archibald is eager to get cracking again.

He said: “The break gets shorter every year. It still seems really quick to be back, but it’s good to be back into it. You do miss the pressure and the whole rigmarole of it starting up again.”