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.