Karim Adeyemi told to 'grow up' as Man Utd & Arsenal eye £75m transfer
Adeyemi told he 'isn't that good' amid Man Utd & Arsenal links

Borussia Dortmund forward Karim Adeyemi has been told he "isn't that good" and must demonstrate greater maturity if he hopes to secure a big-money switch to the Premier League, with both Manchester United and Arsenal reportedly interested.

Dortmund frustration boils over after Gladbach win

The criticism follows Adeyemi's petulant reaction to being substituted during Dortmund's 2-0 Bundesliga victory over Borussia Monchengladbach on Friday night. The 23-year-old, who had returned to the starting lineup, was removed while his side held a one-goal lead and promptly stormed towards the dressing room, only to be intercepted by sporting director Sebastian Kehl.

Kehl did not hold back in his post-match assessment, confirming the player's reaction was unacceptable. "His substitution was completely warranted. He didn't play well," Kehl stated. "He will receive a fine for that... I don't want to see that reaction, the coach doesn't, the team doesn't."

Hamann's brutal verdict on attitude and ability

The incident is the latest in a series of disciplinary issues for Adeyemi this season, which included being charged with possession of illegal weapons last month. Former Liverpool and Germany midfielder Dietmar Hamann delivered a scathing verdict on the player's prospects.

"These indiscipline issues have crept in over the last few weeks," Hamann told Sky Deutschland. "If he doesn't want to be substituted then he should go and play tennis or golf. And he's really not that good."

Hamann argued that only exceptional output could excuse such behaviour, a level Adeyemi has not reached. "If he were scoring 25 goals or more, then I'd say, 'Do what you want', but he's just not that good," he added.

Premier League move hinges on maturity

Despite the controversies, Adeyemi's blistering pace and talent have attracted significant interest. Manchester United are said to have held talks with his agent, Jorge Mendes, while league leaders Arsenal are believed to be the player's preferred destination should he leave Dortmund.

However, Hamann warned that English suitors will be deterred by his current conduct. "He has a huge market in England but they won't even look at him in England if he doesn't grow up," he cautioned. "It's up to him to show Dortmund – or whichever team he wants to join – that he's mature."

With just 18 months remaining on his current contract, Dortmund face a crucial decision. German outlet Bild reports that club directors will meet to discuss a fine for the Gladbach incident. The club is believed to value the Germany international at over £75 million, and may consider a summer sale if his attitude does not improve.