Two goals in the second-half from Vurnon Anita and Yoan Gouffran secured a routine win at Roots Hall.
Goaless first half
It was the League One side that started the better of the two teams, applying heavy pressure to the United back-line.
However, after riding the early storm, Rafael Benitez' men settled and began to create chances. Jonjo Shelvey, Dwight Gayle, Daryl Janmaat and Ayoze Perez all squandered to fire the Magpies into the lead.
The Toon Army ended the half by putting Southend under immense pressure but Phil Brown's players held firm to keep the score level at the break.
Anita goal – great strike
The Dutchman claimed he earlier in the month that he wanted to be “an important player” for Newcastle in an interview with chroniclelive.co.uk.
The 27-year-old has been deployed a defender under Benitez’s reign. Anita has filled in at full-back despite being signed as a central midfielder by Alan Pardew in 2012 - finally Benitez was happy to give Anita his chance to shine in the midfielder - Southend.
And shine he did, coming up with a stunning strike on 48 minutes to beat the The Shrimps keeper from 22-yards after driving forward 13-yards from where he previously won possession.
The Scottish-International didn’t travel with his new team-mates to Belgium on Saturday with the defender looking to improve his fitness as quickly as possible in a bid to cement a place in the Toon back-line.
Grant Hanley was introduced on 62 minutes to replace Chancel Mbemba as he and Jamaal Lascalles went on to keep a clean sheet.
The Gouff is on fire
Gouffran has been surplus to requirement at St James’ Park over the last year after falling out of favour. But in pre-season, Benitez has been keen to give the Frenchman a chance – featuring regularly.
The 30-year-old replaced Rolando Aarons on 62 minutes, and scored 16 minutes later to grab his first goal in 18 months, sparking an internet craze of “The Gouff is on fire”.
It was a clever finish by Gouffran after driving into the penalty area and finishing well into the bottom corner.
Number one goalkeeper – very unclear
After Sels’ error to give away a penalty away at Doncaster Rovers last week, it looked like the race for number one was blown wide open between him and Karl Darlow.
But as the team-sheet was announced on Saturday against Sporting Lokeren, Sels retained his place. And when it looked like Sels was winning the race to start at Craven Cottage a week on Friday, Darlow replaced the Belgian at Southend.
And Darlow went on to get 90 minutes under his belt – impressing with a solid save to dent David Mooney from close range on 89 minutes.
No Matt Ritchie
The 26-year-old missed United trip to Belgium on Saturday and the trip to Roots Hall.
Benitez confirmed to the media three days that Matt Ritchie picked up a knock but it was nothing to major. Fans were hoping to receive a boost by seeing the ex-Bournemouth man on the team-sheet, but he was left at home.
However, Ritchie should be fit to play a part in the game against Vitesse. And if that comes too soon for the midfielder, Fulham should be a certain.