3 things we learned in the Premier League this weekend

Before Swansea City hosts in-form Liverpool on Monday, theScore looks back at a Premier League weekend that provided relief for Arsenal fans.

Toffees caused sticky situation in Watford

When Sky Sports' Soccer Saturday panel criticised Marco Silva last January, the backlash inspired a hipster following for the Portuguese during his survival bid at Hull City. The changes he presided over in Yorkshire indicated he wasn't out of his depth, as Paul Merson and Phil Thompson suggested.

Silva was showcasing his tactical acumen and man management skills again at Watford this season - his Richarlison coup was inspired, and his midfield trio was well-drilled and tireless - so it's no surprise that he drew admiring glances from league rivals. Following years of upheaval at Vicarage Road, the Hornets looked to be implementing a playing philosophy, and maybe even some stability.

Watford blamed the subsequent loss of form on Everton's approach for Silva in November. On Sunday, he was sacked after the previous day's 2-0 defeat at Leicester City.

"The catalyst for this decision is that unwarranted approach, something which the board believes has seen a significant deterioration in both focus and results to the point where the long-term future of Watford FC has been jeopardised," read Watford's statement.

By the time the two teams meet in Hertfordshire on Feb. 24, Javi Gracia will be in charge of his fifth match.

Related: Who is Javi Gracia? Introducing Marco Silva's successor at Watford

The Spaniard's longest managerial stint was two years at Malaga. He'll be lucky to get half that in Watford.

Pochettino puzzles with substitutions once again

Mauricio Pochettino's half-time team talks tend to do the trick, but the Argentinian is often too slow to react or makes the wrong decisions if Spurs don't breach the opposition in the second-half's opening stages.

No top-six team has scored fewer goals towards the end of matches than Tottenham Hotspur, and it's down to Pochettino's bench policy. Christian Eriksen was missed in Sunday's 1-1 draw in Southampton, but the highly-regarded boss wasn't proactive enough. His first substitution was on 70 minutes, which is actually quite early for Pochettino, but the decision to sacrifice confident hitman Heung-Min Son was odd. Moussa Sissoko left Serge Aurier exposed numerous times in the first stanza - Tottenham's right side was exploited before Davinson Sanchez's own goal - and Mousa Dembele was poor again in what's turning into a wholly disappointing term from the Belgian.

Sissoko wasn't withdrawn, and Dembele lasted 85 minutes.

Pochettino is one of the most adaptable tacticians in the division, but there is something lurking - maybe a mistrust of Spurs' backup, or simply poor game management when it comes to handling replacements - that has hindered Tottenham in league draws with Burnley, Swansea, West Bromwich Albion, Watford, and West Ham United.

Swapping concept confuses nation

North American sports are familiar with trading, but in English football it's a confusing concept.

The Mirror's John Cross believed a straight swap of Alexis Sanchez and Henrikh Mkhitaryan wasn't going to happen due to difficulties in organising the paperwork and assessing each player's valuation. But somehow, it seems to be going ahead.

The last box-office trade between two Premier League outfits occurred in 2006, when Chelsea forfeited William Gallas and £5 million to bring in Ashley Cole from Arsenal. Arguably the biggest exchange was made in January 1995, though, when Andy Cole cost Manchester United £7-million plus Keith Gillespie.

But with no transfer fees exchanged to take Sanchez to United and Mkhitaryan to Arsenal, debates on whether these players are of equal value will be aired in pubs up and down the U.K. Sanchez is the better player, but will Mkhitaryan be a better fit in north London?

Related: 5 ways Manchester United can line up with Sanchez

Around the grounds

Burnley 0-1 Manchester United: The Clarets matched Jose Mourinho's side for shots, cracked the woodwork, and were unlucky to go pointless at Turf Moor. United's win contributed to a good day for Arsenal, which possesses an eight-point cushion in sixth place after the 24th round of fixtures.

Related: Why Dyche's grounded approach wouldn't cut it in a top-level job

Arsenal 4-1 Crystal Palace: And what a statement performance it was from the Gunners. Sanchez's impending exit poses more questions of Arsenal's running and ambition - it reopens wounds from the sales of Samir Nasri and Robin van Persie - but a reversion to a back-four temporarily masked issues under Arsene Wenger. It was an overdue tactical shift, providing a comfortable footing at the back and enabling those ahead to delight with fluid attacks. Alexandre Lacazette's strike was the pick of a bunch after it concluded a stunning team move.

Elsewhere:

• Brighton & Hove Albion 0-4 Chelsea
• Everton 1-1 West Bromwich Albion
• Manchester City 3-1 Newcastle United
• Stoke City 2-0 Huddersfield Town
• West Ham United 1-1 Bournemouth

Monday: Swansea City vs. Liverpool

Carlos Carvalhal's Sheffield Wednesday tenure had grown stale, but he's already brought improvements to Swansea. Aside from a loss against Tottenham, Carvalhal took a precious four points from Watford and Newcastle, and impressively booted Wolverhampton Wanderers from the FA Cup over two legs. Even with Jordan Ayew hitting form, it's difficult to envision the host taking points from Liverpool. Jurgen Klopp's side is brimming with belief after last weekend's 4-3 dismantling of Manchester City, and battered the Swans by a 5-0 scoreline on Boxing Day.

(Photos courtesy: Getty Images)