Arsenal loanee Ethan Nwaneri was in Bundesliga action for Borussia Dortmund in their goalless draw with Union Berlin

Ethan Nwaneri could hardly have wished for a more difficult start to life at Borussia Dortmund after joining the German club on loan from Arsenal in the summer. The 19-year-old appeared to be sent off just seconds into Dortmund's Bundesliga clash against Union Berlin on Saturday after catching Tom Rothe with a heavy challenge.

However, Nwaneri's confusion at the decision was swiftly cleared up when referee Daniel Schlager realised he had accidentally pulled the wrong card from his pocket. The official quickly corrected his mistake, showing Nwaneri a yellow card instead and allowing him to continue in the match.

However, the Arsenal loanee struggled to make the desired impact and, having been booked so early in the contest, was substituted shortly after the hour mark. His display was called out by the German media, however.

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Bild described the team's start as 'nothing short of explosive' and Nwaneri's challenge as 'brutal'. Meanwhile, local newspaper Ruhr Nachrichten was unimpressed, awarding him a 5/10 rating and suggesting he has yet to prove his worth.

While Goal claimed Nwaneri was Dortmund's most dangerous player during his 60 minutes on the pitch, other assessments were less favourable, describing him as 'largely anonymous'. Ran was even more critical, giving him a rating of 5 for a 'mostly negative' performance, which was characterised by 'poor ball control' and 'inaccurate finishing'.

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Dortmund sporting director Nils-Ole Book criticised the team for a lack of courage, saying: "We're disappointed. We wanted to do a lot more.

"To get in behind, you need to play with more courage all over the field. We started doing that far too late. When we're bolder, we play really good football and are able to put pressure on our opponents."

The Premier League's youngest-ever player has made seven appearances for Dortmund across the Bundesliga and Champions League. He has started four league matches but is yet to feature in the starting XI for a European fixture.

Dortmund, who suffered a 1-0 defeat to Bodo/Glimt earlier this week, face Azerbaijani side Sabah on Tuesday as they look to secure their second win in the competition.