The 37 year old is likely to retire from playing football altogether but could remain at St Mary's as a coach, either with the first team or the academy.
Lallana was unable to help Saints stave off relegation, and was already in the dugout by the time they passed Derby County's 11 point record.
He made 18 appearances, bringing his Saints total to an incredible 283, but his last start was against Wolves before the November international break.
When Lallana left Saints for the first time in 2014, he was a PFA Player of the Season nominee and primed to be one of England's best players.
On his return, he pleaded with fans: "Coming back is a different pressure, I'm not the same player that I was 10 years ago. I hope people accept that."
Adam Lallana signed a one-year contract with Saints last summerAdam Lallana signed a one-year contract with Saints last summer (Image: PA)
Fans are entitled to whatever opinions they hold about the controversial first departure of their captain, who signed for Liverpool for £25million.
Rather than give an interview, Lallana infamously took out an advert in the Daily Echo to thank fans for their "endless support" over 14 years.
The academy graduate privately felt hurt by the response his transfer prompted, and to this day insists he never acted improperly towards the club.
The Daily Echo advert taken out by Adam LallanaThe Daily Echo advert taken out by Adam Lallana
His return was welcomed by many, with the seal of approval from Matt Le Tissier, who sat alongside him at the Championship play-off final.
Lallana had already agreed to rejoin under former manager Russell Martin, whatever division Saints were in, after his Brighton contract was up.
Lallana claims he wanted to join Saints five years earlier, when he left Liverpool, before eventually signing a deal at the south coast Seagulls.
He spoke to former CEO Martin Semmens and coach Kelvin Davis, but manager Ralph Hasenhuttl was not interested in making the move.
Perhaps if that would have happened, he would have made a bigger impact on the pitch. But even in 2025, Saints gained a leader off of it.
Lallana immediately got to putting an arm around Tyler Dibling, taking personal responsibility for the development of the club's starlet.
"He speaks to us every day, helps us, and if we’re doing something wrong he puts us in line. He’s the perfect role model," said 19 year old Dibling.
"He’s lived what I want to live and he can give me tips on the way to make it. He’s very demanding, but it’s good because that’s what you need."
Adam Lallana pictured with Man City boss Pep GuardiolaAdam Lallana pictured with Man City boss Pep Guardiola (Image: PA)
But it is not only the young players Lallana has been leading, imparting 305 matches worth of Premier League experience on the squad.
Club captain Jack Stephens said: "All season, Ads has been, while officially a player, not necessarily taking sessions but coaching individual players.
"He got as much experience as he could out of his stature as well. It's been really good for me as a captain to bounce ideas off of him."
Lallana missed the opening two matches due to an injury sustained warming up for the first pre-season friendly - even he thought, 'Here we go'.
But when he did play, he was brilliant. It was not quite as though he had been frozen in time, but he had morphed into something ever-lasting.
Had he been fit, he could be a poster boy for the talent is class brigade, who drool over the likes of world class Luka Modric and Toni Kroos.
Lallana combined with Dibling to set up Yuki Sugawara for Southampton's first goal of the season at Brentford, after just 10 minutes on the pitch.
Two weeks later, Lallana fed Dibling as the teenager scored an historic first Saints goal, which should have been a match-winner against Ipswich.
The 17 years and 306 days between the pair's birthday was the biggest age gap between a Premier League scorer and provider since 2006.
It was a perfect twist of fate for the academy example to set up the academy's best budding hopeful for a generation, for his first ever goal.
Lallana knows opinions on him will always be split around these parts and he hoped he could repay any fan who felt let down, but it was not to be.
With the pedigree he has established in football, Lallana can dictate his future and will not be short of offers to work in dugouts across the country.
Saints would like to keep him around and with his son, Arthur, moving into the club's under-13s team, that should tug on his heart strings more.
Lallana was a vital part of Southampton's rise from League One to Europe, but could not save them this time. Football is not always fairytales.