Jim Goodwin believes it is a “crying shame” that Aberdeen new boy Callum Roberts is out for “eight to 10 weeks” with a hamstring injury.

The 25-year-old attacking midfielder, who signed from Notts County last month, came on as a substitute in last weekend’s 4-1 cinch Premiership win over St Mirren at Pittodrie but had to go back off again.

Ahead of the home game against Motherwell on Saturday, Dons boss Goodwin was happy to confirm Hayden Coulson’s knock was not as bad as first feared, but he had more gloomy news about Roberts.

He said: “The scans for Hayden Coulson’s injury were better than first feared initially.

“This weekend is going to come too soon for him unfortunately but he will be back in the squad at the early part of next week.

“And Callum Roberts, unfortunately, his one is worse than we thought initially. And it looks as if Callum is going to be out for quite a significant period of time.

“It is a hamstring, unfortunately, tendon just behind his knee.

“He will go and see a specialist this afternoon (Thursday) actually, he’s got a meeting at 5.30pm with one of the consultants and then there will be a decision made next week about how to treat that, but it is looking probably eight to 10 weeks I would imagine.

“It’s never ideal. I’ve been in that position myself as a player.

“When I first signed for Scunthorpe many years ago I broke my ankle in one of the first pre-season games and sat out the next 12 weeks.

“It’s a crying shame for the boy because when you are that new player, all you want to do is go and prove to the manager, the staff and the players that you belong here and obviously show the supporters why you’ve been brought to the club.

“He’s a very good player, very attack-minded, creative, scored a great deal of goals last season for Notts County and I felt he was going to be a great addition to the group.

“So we’re just going to have to be a little bit patient with that one now and bide our time and look forward to seeing him in a couple of months’ time.”

Meanwhile, Goodwin is pleased that Steven Hammell has been appointed as permanent manager of Motherwell after a short spell as interim boss.

The 40-year-old former Well left-back, who leaves his previous role as academy director, has signed a two-year contract and has named Brian Kerr as his assistant.

The Irishman said: “Firstly, I have got to congratulate Steven. I think it is a great appointment by Motherwell.

“I am delighted to see another young manager being given an opportunity. The Motherwell board deserve a lot of credit for that because it is very easy to go down the tried and tested route.

“But with Steven coming in, I think we will get a freshness to the league, he will have a different vision and strategy for how he wants to take Motherwell forward and I’m looking forward to seeing what brand of football he brings to the league. I wish him every success from Sunday onwards.”