Everton secured their first three points of the season as they beat Stoke City 1-0 in their Premier League opener.
It was Wayne Rooney who ensured the Toffees took maximum points, as he headed in his first goal for Everton since his return to the club after 13 years away at Manchester United.
It was destined to be for England's all-time top goal-scorer, as the passion on his face upon netting reminded the Goodison faithful of his famous 'Once a Blue Always a Blue' shirt, shown to the crowd during his first spell at the club which ended in 2004.
It wasn't plain sailing for Koeman's men, however, as the lifeless first half and Jordan Pickford's sensational save late on proved. So, what did we learn from Everton's opener?
Koeman must solve the right back conundrum
With Everton's regular Seamus Coleman still recovering from a double leg break last season, the right-back position was bound to be contested tightly.
Pre-kick off and Everton fans were left dumfounded by Koeman's starting 11; whilst the majority of the team choice was to be expected, the inclusion of Dominic Calvert Lewin at right-wing-back was a confusing one.
With the introduction of Dutch full-back Cuco Martina on a free transfer in July, it seemed Koeman was aiming to temporarily patch up the Coleman shaped hole with a player known to him from his time at Southampton. However, the unconvincing performances from the 27 year-old in pre-season and in the second half of today's game means the question as to who can cover for the Irishman remains.
The obvious answer would be to implement 20 year-old Mason Holgate, who appeared a total of 21 times for Everton last season. While impressing in a number of games, Holgate looked inconsistent at times, and failed to get a good run in the team.
This has left a large number of Evertonians calling for Kirkdale born Jonjoe Kenny to be given a chance after an incredible 2016/17 season in which he captained Everton's under-23's to league victory, as well as featuring as England's under-20's first choice right-back in their World Cup success. However, despite impressive showings in pre-season, it appears the 20 year-old isn't ready in his manager's eyes, as he was left out of the preliminary squad this weekend.
The youth must continue to be offered chances
Despite Dominic Calvert Lewin being deployed as a wing-back during the first half of the game and clearly being out of his depth, the young Englishman shone when moved up into his natural striking role alongside new signing Sandro Ramirez.
After scoring the winner in the Under-20's World Cup, the youngster has been full of confidence, and has shown it, as he scored the winner in Everton's second leg victory against Ruzomberok in the Europa League qualifying round.
The Yorkshireman isn't alone in making his way into the Everton first team either, with Ademola Lookman also being on the fringes of first team action. The two front men follow in the footsteps of Academy graduate and fan favourite Tom Davies, who tallied a total of 25 appearances last season.
Not only is it important to give the youth a chance now in terms of squad rotation and early experience, but it will come as extremely beneficial in the long run, with Wayne Rooney being a prime example of this.
The Summer transfer window has been a success
A couple of seasons ago, no-one would have guessed that Everton would have spent just over £100 million with little over two weeks remaining.
Big Summer signings Michael Keane (£16 million), Jordan Pickford (£14 million), Wayne Rooney (£14 million), Davy Klaassen (£16 million), Sandro Ramirez (£9 million) and Cuco Martina (free) all featured in the opening fixture, and showing positive attributes in every area of the pitch.
Rooney's return has been received as expected, and was celebrated with admiration after his opener today. His first half strike partner Sandro Ramirez looked lively, as he demonstrated his skilful nature on several occasions, whilst Klaassen's determination and visions was highlighted on a couple of occasions.
However, it is the arrivals of Michael Keane and Jordan Pickford that will potentially boost Everton most this season; Keane had a fantastic season with Burnley last time round, despite their near relegation miss - and can help with Everton's ageing defensive unit, whilst Sunderland's relegation could have been much more graphic if it was not for the 135 saves made by the 23 year-old last season.
With an average age of arrivals being 24, it is clear to see that Koeman is looking to build for the future, all the while each 20-something has shown composure and talent beyond their years.