David De Gea: Manchester United's 1-0 Defeat at Newcastle Unacceptable

Manchester United goalkeeper David De Gea has said his side's 1-0 defeat at Newcastle United on Sunday "isn't acceptable," adding this is probably his "most difficult time" at Old Trafford since he arrived.

The Red Devils succumbed to the Magpies after Matthew Longstaff, 19, scored the only goal at St James' Park, leaving United with one win and only two goals scored in their past five games.

De Gea railed against his side's recent results after the match, per BBC Sport: "The game isn't acceptable. The whole season isn't acceptable for us."

He then spoke to Sky Sports and added: "We didn't create any proper chances. We have a lot to improve. I don't know what to say. We need to step up. We have injuries but it's not an excuse. We are Manchester United. We need to train hard to keep fighting and to get back to winning games."

United hit the target on three occasions compared to Newcastle's two accurate attempts, per WhoScored.com, with Longstaff—younger sibling to midfield team-mate Sean—settling the result:

Ole Gunnar Solskjaer's side have now failed to score in their last two matches following their 0-0 UEFA Europa League stalemate at AZ Alkmaar on Thursday. 

De Gea continued to say United must "keep fighting" to improve: "It's probably the most difficult time since I've been here. I don't know what is happening. We cannot score even one goal in two games. Sorry to the fans. We will keep fighting, for sure. We will come back, but at the moment we're in a difficult situation."

Solskjaer's men have won two of their eight Premier League games this season (drawn three, lost three), and the team sit 12th in the table approaching the quarter-way mark in the campaign:

De Gea, who arrived at Old Trafford from Atletico Madrid in 2011, signed a new contract in September that will keep him with United until at least the summer of 2023.

Journalist Samuel Luckhurst provided more comment from Solskjaer, suggesting not enough has been done to transform the team following a miserable spell in their history:

United have kept three clean sheets in their past seven games, but it appears the shift toward a more defensive focus has resulted in the team losing much of its attacking potency.

The international break could be well-timed in that it allows Solskjaer's side to regroup and strategise, though it's difficult to see where United can look for inspiration at present.

United will host Premier League leaders Liverpool when they return to Premier League action on Oct. 20, when they will risk going four matches without a win for the first time this season.