He joined Hednesford Town in the West Midlands (Regional) League, winning the Staffordshire Senior Cup in his final appearance for the club in 1970.
He returned to his former club Brighton & Hove Albion as manager in February 1998, who were struggling near the foot of the Third Division and forced to play home games at Priestfield Stadium in Gillingham.
He spent 2011 as Phil Brown's assistant at Preston North End and then returned to management with Macclesfield Town in March 2012, though he was unable to prevent the club from being relegated from the Football League.
He joined Doncaster Rovers as Paul Dickov's assistant in June 2013, before he was appointed as football coordinator at Southend United by Phil Brown in August 2015.
[7] Horton had been earning £7-a-week at Hednesford, rising to £20 with win bonuses, supplemented by a £20-a-week income from building work, and so actually took a significant pay cut to turn professional at Port Vale on wages of £23-a-week.
[9] A first-team regular from the start under manager Gordon Lee, Horton played 40 games in the 1970–71 season, and scored his first competitive goal in a 3–2 win against Bury at Gigg Lane.
[8] He missed a period around Christmas due to injury, and during this time his teammates struggled to find results; this ultimately cost the "Valiants", as they finished four points behind promoted Notts County.
[10] The injury had come in a 2–0 defeat at Charlton Athletic, when a knee-high tackle left him with a hairline fracture of the leg, which also caused him to miss an FA Cup third round tie with West Ham United.
[17] Albion made a fourth-place finish to the 1977–78 season, missing out on promotion to the First Division only because third-placed Tottenham Hotspur had superior goal difference.
The team got off to a poor start amidst discontent with the club's board over bonus pay, losing four of their opening five games and sinking to bottom of the league by November.
[5] He was named on the PFA Team of the Year for the third time in his career, alongside teammates Kirk Stephens, Ricky Hill, and David Moss.
The club faced a financial crisis following the mysterious death of Robert Maxwell, and over the summer, Horton was forced to sell striker Martin Foyle to Port Vale for £375,000.
[43] The loss of close to £1 million of talent showed on the pitch, as Oxford ended the 1991–92 season one place and two points ahead of relegated Plymouth Argyle.
But then Horton transformed his attack by signing Uwe Rösler (Nürnberg), Paul Walsh (£750,000 from Portsmouth) and Peter Beagrie (£1.1 million from Everton), and City escaped relegation after losing only two of their last 14 games of the season.
[47] City were sixth on 3 December and there was talk of a much-awaited return to European football, as young talents such as Garry Flitcroft, Richard Edghill, and Steve Lomas came to the fore.
[58] Aiming for a complete overhaul of the playing squad and unimpressed by the reserve and youth teams, Horton told chairman Dick Knight "I want 18 out and 18 in".
[59] Other signings included Jamie Moralee (Crewe Alexandra) and Ian Culverhouse (Kingstonian), whilst he brought Martin Hinshelwood and Dean Wilkins onto the backroom staff.
[62] This spending spree set the club back £630,000, and so Horton first sold off Peter Beadle to Notts County for £250,000 to raise the cash needed for his new signings.
In their place he signed Micky Cummins, Mark Goodlad, Sagi Burton, and Ville Viljanen; and also took Martin Bullock, Gareth Taylor, and David Healy in on loan.
[67][68] Horton came under pressure from the board at the start of the 2000–01 campaign, as his team went 13 games without a win,[69] and were knocked out of the FA Cup by non-League Canvey Island.
[72] He signed Steve Brooker for £15,000; brought in Onandi Lowe and Richard Burgess on free transfer, whilst also offloading Jeff Minton to Rotherham United.
[76] This meant Horton had to build his squad for the 2001–02 season entirely on free transfers, the most influential proving to be former Coventry City striker Stephen McPhee.
[77] Horton signed Jon McCarthy, Brett Angell, Ian Brightwell,[78] Phil Charnock, Sam Collins,[79][80] and Mark Boyd[81] for the 2002–03 campaign.
[89] He found his replacement in Everton's reliable young George Pilkington;[90] he also signed goalkeeper Jonny Brain and Austrian defender Andreas Lipa.
Over the summer he signed Iraqi international Jassim Swadi,[98] experienced striker Mike Sheron,[99] veteran defender Tony Barras,[100] left-back Mark Bailey,[101] and Tommy Rooney.
[105] He later added to his squad by signing Mark Boyd[106] and Simon Weaver;[107] whilst transfer listing Tommy Widdrington and Michael Welch.
[113] Macclesfield qualified for the play-offs in sixth place, but their promotion challenge was finally ended by Lincoln City in the semi-finals, following a 2–1 aggregate defeat.
[131] He also signed versatile attacker Colin Heath,[132] defender Carl Regan,[133] and former Port Vale goalkeeper Jonny Brain;[134] whilst releasing five players.
[139] In March 2009, Horton was featured heavily in the press after accusing Arsenal club captain Cesc Fàbregas of spitting following an encounter in the FA Cup.
[142] The "Tigers" struggled in the 2009–10 season, and Phil Brown was put on gardening leave on 15 March, as Horton and Steve Parkin were appointed as the club's joint-caretaker managers.