David de Gea heroics and safety-first Man United hold Liverpool

LIVERPOOL -- Three quick thoughts on Liverpool 0-0 Manchester United in the Premier League on Saturday afternoon.

1. De Gea preserves a point for United

David de Gea produced a stunning first-half save from Joel Matip in a commanding performance at Anfield as Manchester United held firm against Liverpool to extend their unbeaten start to the season.

Almost a year to the day since scraping out a dismal 0-0 stalemate at Anfield, United emerged with the same result after creating just one clear chance -- a Romelu Lukaku strike, which was saved by Simon Mignolet -- on a day when their defensive discipline proved decisive.

Liverpool, without the injured Sadio Mane, dominated the game for lengthy periods, but aside from Matip's first-half effort, which was kept out by de Gea's left leg, the home side were unable to put the United goal under sustained pressure.

Jurgen Klopp's team lacked the attacking threat they displayed during August's 4-0 win against Arsenal, and their run of results since that game now stands at one win in eight.

United, meanwhile, avoided defeat thanks to de Gea's heroics and a disciplined approach, although their lack of attacking intent in their first real test of the season will lead to further questions about Mourinho's approach in big games. But they remain unbeaten after a fixture that is traditionally one of the more difficult on their calendar.

Both managers will take positives from the outcome and performance of their teams, but it was certainly no classic.

2. Liverpool must find a way without Mane

Mane's hamstring injury, sustained on international duty with Senegal, was a hammer blow for Liverpool ahead of this game, but Klopp must come up with a Plan B to avoid his anticipated six-week absence from completely derailing his team's season.

With Mane in the team, Liverpool possess blistering pace and his ability to hit even the best teams on the break in ruthless fashion.

But without him, Liverpool are so much easier to defend against, and Manchester United were largely untroubled at Anfield with Mane watching from the sidelines.

Mohamed Salah possesses pace, but the Egyptian is not in the same league as Mane when it comes to escaping his marker. Roberto Firmino and Philippe Coutinho, meanwhile, prefer to play off the frontline rather than run beyond it.

Liverpool are fortunate that few teams will face them with the same kind of defensive discipline that Jose Mourinho has instilled into his United team, but opponents will have watched this performance and realised that you can sit deep against Liverpool and blunt their edge without Mane.

And with a squad lacking any kind of height or physical presence, Klopp cannot switch his approach like Mourinho can for United.

So defending against Liverpool without Mane in their lineup is quite simple -- sit deep and pick defenders who tower over the Merseysiders' forwards.

Klopp does not have many alternative options in his squad, so he needs to come up with a new plan.

3. Mkhitaryan fails to deliver in big match ... again

Henrikh Mkhitaryan was briefly trending on Twitter shortly before half-time in this game at Anfield, with the joke being that he could make a game-changing intervention from the bench for Manchester United in the latter stages.

The punchline, of course, was that Mkhitaryan was already on the pitch, having been named in Mourinho's starting team against Liverpool, but the Armenian had been so anonymous and ineffective that it would not be difficult to believe that he had actually watched the game from the substitutes' bench.

Mkhitaryan is unquestionably a gifted footballer, and he has raised his game this season after a difficult first year at the club following his arrival from Borussia Dortmund in the summer of 2016.

The midfielder has created numerous goals and scored two himself so far this term, but as ESPN FC reported last month, Mourinho continues to want more from the 28-year-old in finely balanced games against United's biggest rivals.

The theory about Mkhitaryan among Mourinho and his coaches is that he can deliver more against the top teams but too often fails to do so.

But if Mkhitaryan disagrees with that perception, he did not do anywhere near enough against Liverpool to prove Mourinho wrong.

He did not look to dominate the game or cause problems for Liverpool and, as a result, Lukaku was starved of service as a long forward.

When Mkhitaryan was replaced by Jesse Lingard just after the hour mark, it was long overdue because he had been so poor against United's greatest rivals.

On this evidence, Mourinho cannot trust him to deliver against the likes of Chelsea and Manchester City.