Karl Hein, the third-choice goalkeeper at Arsenal, has claimed that the club stopped him from leaving on loan in January despite interest from other clubs. The 21-year-old shot-stopper is yet to make a senior appearance for the Gunners in the Premier League this season, with David Raya and Aaron Ramsdale ahead of him in the pecking order. Hein made his only first-team appearance in a 3-1 defeat to Brighton in the Carabao Cup back in November, a game in which he was heavily criticised. Hein admitted that playing time is crucial for his development, especially as a young goalkeeper. He mentioned…