FA Cup stats: Liverpool, Jose Mourinho, Notts County, Will Grigg

Have the January blues hit Liverpool again? Will Grigg's on fire, Jose Mourinho's 100th Manchester United game and the League Two team with plenty of Premier League experience - we look at some of the stats from the FA Cup this weekend.

Wigan's defeat of West Ham was the big upset in the fourth round.

Elsewhere, Harry Kane spared Tottenham's blushes with a late equaliser against League Two Newport County, while Notts County also earned a replay against Swansea.

Chelsea, Manchester United and Manchester City all progressed without trouble, but Liverpool are out after their 3-2 defeat by West Brom.

• Watch all the FA Cup goals

• Batshuayi double sees Chelsea past Newcastle

• Sane injury mars Man City win at Cardiff

January blues for the Reds?

Liverpool's defeat means they have lost in the FA Cup fourth round in all three seasons under Jurgen Klopp.

The last time they got beyond the fourth round was Brendan Rodgers' last full season in charge in 2014/15 when they lost 2-1 to Aston Villa in the semi-finals.

And speaking about Rodgers, defeat to West Brom means Klopp has won fewer games than his predecessor after the same number of games in charge.

The defeat to West Brom also ended Liverpool's 19-game unbeaten home run - it was their first defeat at Anfield since a 2-1 defeat by Crystal Palace in April 2017.

Coming on the back of Monday's defeat at Swansea in the league, it also raises questions about whether Klopp's side are suffering another wobble in January.

Last season they beat Manchester City on 31 December, 2016, but then went on a dreadful run, losing an EFL Cup semi-final, being knocked out of the FA Cup and dropping from second in the table to fourth by the end of January 2017.

January 2018 could not have started better for the Reds, with four consecutive wins, the last of those being the stunning 4-3 victory against City, which was supposed to be their watershed moment.

But all that good work has been undone by damaging back-to-back defeats to bottom side Swansea in the league and the cup exit to the Baggies, leaving the Champions League as their only realistic chance of winning silverware this season.

Last January, Liverpool were without Sadio Mane, who was at the African Cup of Nations, while Philippe Coutinho, Joel Matip, Nathaniel Clyne and Jordan Henderson were all out injured.

This season they have sold Coutinho to Barcelona for £142m and are currently without injured trio Adam Lallana, Ragnar Klavan and Clyne.

Centre-back Virgil van Dijk has been brought in for a world-record £75m deal and time will tell if the Dutchman can add steel to their defence.

Perhaps it's the added pressure of being back in Europe, but Klopp has made almost three times the number of changes to his starting line-up in the league than in 2016/17.

The Reds have also sprinted less and run less, despite sticking with their 'gegenpressing' style of play. They have run 2,732.3km this season, the fifth highest in the league, but that is down on the previous season.

If tiredness is an issue, the last thing they will want is four games in the next two weeks, ending with a trip to Porto in the Champions League.

Their visit to struggling Huddersfield on Tuesday should tell us if this will turn into a proper wobble or not.

How is Mourinho doing after his first 100 games?

Mourinho reached his century for Manchester United at Yeovil's Huish Park on Friday and celebrated with a 4-0 win, which came on his 55th birthday and a day after extending his contract at Old Trafford.

It's not been an easy start to life in the north west for the Portuguese, despite winning the EFL Cup and Europa League in his first season.

A win percentage of 62% is the second lowest of his career after 100 games, only slightly better than he achieved with Inter Milan after 100 matches.

Of course, he went on to win the Champions League, Serie A and Coppa Italia in his second season in charge in Italy, before moving to Real Madrid.

Blast from the past

A team second in League Two had more Premier League experience in their starting XI on Saturday than their Premier League opponent.

At times, Saturday's FA Cup tie between Notts County and Swansea sounded like a game out of the early 2000s in the top flight as ex-Newcastle striker Shola Ameobi played a role in ex-Blackburn, Sheffield United and Sunderland striker Jon Stead's equaliser.

Add in ex-Bolton right-back Nicky Hunt, former Stoke defender Carl Dickinson and ex-Portsmouth defender Richard Duffy and it was blast from the past at Meadow Lane.

Then there was 37-year-old former Manchester United, Leeds and Newcastle midfielder Alan Smith, whose late cameo boosted that number even further.

Smith, who is a player-coach at Meadow Lane, has 285 top-flight appearances to his name.

It is perhaps no surprise though, as County are managed by ex-Bolton, Newcastle and West Ham captain Kevin Nolan, who made 401 Premier League appearances.

Stead in good company

Stead's goal has put him among the top scorers so far in 2018 in England's top four divisions.

The 34-year-old has six goals in all competitions since the turn of the year, level with Spurs' Harry Kane, who scored his 30th goal of the campaign against Newport, and Fulham's 17-year-old left-back Ryan Sessegnon, who bagged two against Barnsley in the Championship on Saturday.

Leading the way is Manchester City striker Sergio Aguero on eight.

Behind the leading pack are nine players on four goals including Eden Hazard, Jay Rodriguez and Wigan's Will Grigg.

'Will Grigg's on fire'

Speaking of Grigg, the Northern Ireland striker was very much on fire against West Ham in their 2-0 win, bagging both goals at the DW Stadium in a performance that even drew the praise of Germany and Bayern Munich defender Jerome Boateng.

Grigg's brace took his FA Cup tally to six this season and he leads the scoring charts in the competition, with a goal every 56 minutes.

In second place on five goals are Exeter's Jayden Stockley and Peterborough's Jack Marriott.

And here's one to make some of you feel old.

During their win over Newcastle, Chelsea became the first English top-flight side to field more than one player born in the 21st century in a single domestic match, with 17-year-olds Ethan Ampadu and Callum Hudson-Odoi, who were both born in 2000. both coming on as subs.

Chelsea's young guns - Callum Hudson-Odoi and Ethan Ampadu