Arsene Wenger picked an understrength side for Arsenal's clash against Manchester United at Old Trafford on Sunday afternoon.With the second leg of their Europa League semi-final against Atletico Madrid clearly on his mind, the Frenchman decided to play multiple fringe players.David Ospina, Konstantinos Mavropanos, Ashley Maitland-Niles and Reiss Nelson were all given the opportunity to impress.And that gamble so nearly paid off, after Arsenal held their own for much of the game, but conceded a last minute goal to give the home side all three points.Paul Pogba broke the deadlock after 16 minutes, before Henrikh Mkhitaryan restored parity five minutes after half-time. But Marouane Fellaini's header with just a few minutes remaining gave the home side the victory.Arsenal can no longer finish inside the top four, but their spirited performance does at least provide the squad with a confidence booster going into their crucial second leg against Atletico on Thursday.

KONSTANTINOS MAVORPANOS WAS HANDED HIS DEBUT

Konstantinos Mavropanos made the move to Arsenal from PAS Giannina in January, but prior to today's game, fans had not yet seen him in first team action.

He was handed his opportunity today, and it must be said, he had a very good debut.

At just 20-years-old, some would have expected the defender to have struggled making his debut on such a big stage.

But he did not look overawed as he put in a composed performance. Playing alongside Callum Chambers, the two looked comfortable as they kept Romelu Lukaku quiet for the majority of the game.

His performance attracted great attention from Arsenal fans, with many of them seriously impressed with how he faired on his Premier League debut.

Some have even stated how he is already showing signs that he is better than Shkodran Mustafi.

And some have gone as far as saying that they would like to see the youngster start against Atletico Madrid on Thursday. Interesting.

Interesting stuff.

Mavropanos had a brilliant debut, it must be said.

Starting him against Atletico in their second leg on Thursday would be a huge gamble, but given their struggles in the centre of defence this season, it could be a gamble worth taking for Wenger.

Regardless whether he features in Madrid, at 20-years-old, the £2.2 million that Arsenal decided to spend on him already looks like money well spent.

He's only one game into his career in north London, but if he can maintain the level of performance that he showed against Man United, he could be a starter for Arsenal for many years to come.

Should Mavropanos start against Atletico on Thursday? Have your say in the comments section below.