Gordon Strachan has added former Scotland international Callum Davidson to his backroom staff for the 2018 World Cup qualifier against England.

The St Johnstone assistant manager, who won 26 caps for his country between 1998-2009, will join Strachan and Mark McGhee for the Auld Enemy clash at Hampden on June 10.

He replaces Aberdeen assistant Tony Docherty, who was involved in the previous qualifier against Slovenia in March after Andy Watson left his role as assistant coach.

Speaking to the Official Scotland Podcast, Strachan said: "There's a freshness and enthusiasm about him.

"We had a meeting to make sure we know each other and he understands his remit. He is very happy with that, he is going to be doing nothing different to what he has done at St Johnstone.

"They have had a great season. We have done our homework and everyone speaks highly of Callum. He has also been an international player and knows what is needed."

Strachan went on to explain why his number three role has been changing on a game-by-game basis.

"It will be good to have someone there permanent but it chops and changes because of circumstances," he said.

"Because these guys at the clubs really are called upon to do a lot more than just coaching."

"I met Doc and he is a great coach and a good friend now, which is a bonus. He is always there to be called on."

Meanwhile, the manager revealed the thinking behind cutting five players out of his 29-man squad on Monday.

Kenny McLean, John McGinn, Jamie Murphy, Jack Hamilton and Steven Fletcher all dropped out.

"I don't want to waste anybody's time," he said. "It's precious the time you spend with your family at this stage of the year and vital they get rest as well.

"I don't want a squad of 26 and three players don't get stripped because that's demoralising. So we will cut it down to 23 and hopefully it's worthwhile if you have that strip to take home to show your family.

"If someone gets injured, we will go with one less, I don't have a problem with that."