Aberdeen have signed midfielder Matthew Longstaff on a season-long loan from Newcastle United and agreed a fee for Hamburg centre-half David Bates.

Scotland cap Bates, the 24-year-old who left Rangers for Hamburg in 2018, is out of favour at the Bundesliga 2 club.

The 21-year-old Longstaff has yet to play a senior game this season.

Aberdeen manager Stephen Glass said: "For a young player, Matty has already played in a good number of high-profile games for a top club."

Longstaff, who scored on his Premier League debut against Manchester United in October 2019, has made 20 appearances for Newcastle, including 15 last season, finding the net three times.

"We are pleased he has chosen Aberdeen to help him further his career, particularly as he had other high-profile options in England to consider," Glass told his club website.

"We've no doubt he will have a positive impact and will help us with the rest of our campaign."

Longstaff signed a new two-year contract with Newcastle last summer and, earlier on Friday, manager Steve Bruce had explained that "the kid is desperate to go and play football".

"Aberdeen is a good club and a decent place to go and play, so good luck to him," Bruce said.

"It's happened very, very quickly over the last couple of days. We've said now for a good couple of weeks it's important for young Matty to go and play some football.

"He had a difficult year through one thing and another last year, so it's a great opportunity for him to go and play. It's quite as simple as that."

Bates, who has four Scotland caps, spent last season on loan to Cercle Brugge in Belgium's top flight and previously was sent to Sheffield Wednesday by Hamburg.