Doohan still has to complete the formalities but Kettlewell is confident the Scotland Under-21 international will be in his side to face Motherwell in Monday night's Scottish Premiership opener.

The County boss told the PA news agency: "The agreement is there in principle. Ross is travelling up just now for a medical and I'd be pretty confident we'd have him on the training pitch tomorrow.

"It's been a slight frustration as we'd liked to have got him in before and I'm sure Celtic will tell you they'd like to have had business done a couple of weeks earlier too.

"It's just been one of those domino chains where we knew once Celtic got a new goalkeeper in, Ross would come up to us.

"We've been patient because it's important we give ourselves good options in every area."

Doohan registered 80 appearances for Championship outfit Ayr during a two-year loan stint at Somerset Park, keeping 29 clean sheets.

And Kettlewell is eager to see how he fares in the top flight.

He said: "We've watched Ross over the last couple of years. He did exceptionally well at Ayr and as a young guy, he's got a great mentality for his position.

"He wants to make strides in his career and hopefully we can facilitate that over the next year or so.

"When you look at some of the goalkeepers Celtic have had, then it's extremely difficult for these young guys to break through.

"Celtic have just spent millions on a new goalkeeper while they had someone like Fraser Forster in last season, so it's very tough.

"But from my point of view he stuck out like a sore thumb when we came across him the year we won the Championship.

"I believe that people need opportunities and we're hopeful he can go from strength to strength here."