3 things we learned in the Premier League this weekend

With another round of Premier League action in the books, we take a look back at what happened in the English top flight over the weekend.

New season, same Arsenal

This season was supposed to be different for Arsenal.

Blessed with arguably the deepest squad in the Premier League and perhaps the very best player in Alexis Sanchez, and having found the central midfielder (Granit Xhaka) and defender (Shkodran Mustafi) required to provide the spine the club has long been desperate for, the Gunners were expected to mount a legitimate title challenge.

That hope evaporated Saturday.

Related: 3 upgrades Arsenal needs to mount a real title challenge next season

Chelsea, seemingly strolling to the Premier League crown, opened up a 12-point lead on Arsene Wenger's side with a 3-1 victory at Stamford Bridge, capping a miserable week for the north London club that has incensed supporters and reinvigorated those desperate for the lanky French tactician to be replaced on the bench.

Chelsea's excellence, fueled by the ridiculous Eden Hazard, needs no explanation; barring a colossal collapse, the Blues should saunter to the league title.

Arsenal's continued inability to get over the hump, on the other hand, will keep analysts busy for some time. Mentality? Injuries? Wenger's tactical rigidity? So many questions.

They'll continue to be asked for at least another year.

For now, though, the Gunners' focus needs to flip to qualification for next season's Champions League; five teams are fighting for three spots in England, and Wenger's continued employment at the Emirates likely hinges on his side not being left on the outside looking in.

Step aside, Sergio

Manchester City has a new hero.

Brazilian teenager Gabriel Jesus was once again the name on everyone's lips after the 19-year-old netted a brace - including a 92nd-minute winner - Sunday against Swansea City, a performance that simultaneously generated unbridled enthusiasm about the club's future and intrigue over its present.

If Jesus, surrounded by fellow young studs Raheem Sterling, Leroy Sane, and Kevin De Bruyne, is the preferred option for Pep Guardiola - which he certainly seems to be at the moment - what becomes of incumbent star Sergio Aguero?

Related - Second-choice Sergio: 4 potential summer destinations for Aguero

An elite scorer - arguably the best in the league - who will forever be an icon at the Etihad, Aguero won't be content sitting on the bench. He has long pledged a return to Argentina with Independiente when his contract expires, and despite Guardiola's claims earlier in the season that the 28-year-old has agreed an extension until 2020, the end may be coming sooner, and more abruptly, than anyone expected.

For his part, the Argentine striker knows his spot in the team is no longer guaranteed.

"I will work hard for the remaining three months and then we'll see if the club wants me," Aguero told reporters after Sunday's defeat of Swansea. "I want to stay.

"I am fine. It is normal. Sometimes this happens. When you're on the bench, you have to wait for your opportunity. I have to help the team as much as I can in these three months."

Somewhat ominously, he added: "Afterwards we'll see what the club wants to do with me."

Leicester City is in serious trouble

They can't possibly pull this off, right? Just months apart, that question carries significantly different connotations when aimed at Claudio Ranieri's Foxes.

Leicester City succumbed to a fourth consecutive Premier League defeat Sunday, a 3-0 hammering at the hands of Manchester United that drove last season's fairy-tale champion to within a point of the relegation zone.

The numbers make for harrowing reading.

Those four league losses have seen Ranieri's debilitated lot ship 10 goals without netting any in response as the club comes thumping down violently from the lofty perch of last year's unforgettable triumph.

Related: Floundering Leicester sets unwanted record for scoring ineptitude

The Italian gaffer, under intense scrutiny over both his tactical selections and his apparently souring relationship with those behind the scenes at the King Power, continues to say all the right things in the face of increasing criticism.

"We're together. I'm happy with the players and they're happy with me," he said after Sunday's latest setback. "We have to stay together and keep fighting."

Unlike last season's fight for silverware, this will be a scrap for survival.

Around the grounds

Who's the best striker in England? Diego Costa, Zlatan Ibrahimovic, Harry Kane, and Sergio Aguero typically comprise the responses to that probe.

Romelu Lukaku, meanwhile, is often inexplicably left out of the conversation. It's time to rectify that. The burly Belgian battered Bournemouth single-handedly Saturday, his four goals moving him to 16 on the campaign, good enough for top spot in the league scoring table.

And it's not an aberration or one-season wonder, either. Lukaku's legit, and has been for a while.

(Courtesy: Squawka)

Yes, his sometimes lethargic play turns some people off, but at just 23 years old, Everton's protagonist is already a force of nature, and he's only going to get better.

The weekend wasn't nearly as enjoyable on the red half of Merseyside.

Jurgen Klopp's sputtering Liverpool side huffed and puffed and failed to produce the final product once again, the Reds seeing their worrying winless streak in all competitions pushed to five matches after a 2-0 setback against Hull City.

Related - Klopp: 'We will and have to take all the criticism' after defeat at Hull

Be it fatigue, a lack of overall squad quality, or simple bad luck, the gregarious German gaffer needs to sort things out quickly, lest a once-promising season erode entirely.

Elsewhere

• West Brom 1-0 Stoke City
• Watford 2-1 Burnley
• Southampton 1-3 West Ham
• Tottenham 1-0 Middlesbrough
• Crystal Palace 0-4 Sunderland