Blues needed to avoid defeat to maintain their push for silverware into their final two fixtures of the campaign but, despite Kenny Coker giving them the lead shortly before half-time, strikes by Charlie O’Connell and Adler Nascimento in the final 13 minutes determined their destiny.

It was a tough result for the teenager Shrimpers to take, especially given that Tayo Adedoja had been brilliantly prevented from doubling the advantage shortly before Peterborough’s 77th minute leveller. However, Heath revealed the squad would not be licking their wounds for long.

“The best possible finish now is second in the table, and that’s what we’ll be looking to do,” he confirmed. “There’s no time to be disappointed; we have to dust ourselves down and refocus.

“The U17s have a friendly against Watford in midweek and then we travel to Gillingham on Saturday, and we have to show more quality on the ball and get enough points to secure second. Then we can set ourselves the next target. In football there is always another game.

“We’ve had a chat about it as a group, and we’ve studied the GPS tracking of the players. The lads recognise they didn’t perform to their best, but they definitely put a shift in. The data shows the least distance covered by one player was 13.2 kilometres, and the most was 16.2km.

“However, a lot of that work was done without the ball, and we would’ve liked to have had more possession and dominated the ball more,” he added.

There was just one change to the starting line-up from the two previous thrilling fixtures with U16s goalkeeper Finley Purcell replacing fellow schoolboy George Murray-Jones to make his competitive youth team debut. Left-back Louie Arrowsmith was fit to start following the injury he sustained setting up the opening goal against Northampton Town.

In blustery conditions at Peterborough’s training ground in Orton Longueville, the hosts made the better start to the game, with a couple of penalty shouts waved away by the referee. Ricky-Jade Jones also lobbed over for Posh, whilst Flynn Clarke’s delivery was sent off-target by a stretching O’Connell.

After weathering that early storm, Blues began to grow into the game and force some pressure of their own, although they were indebted to Purcell for making a fine stop to deny Jones before Hameed Ishola sent the rebound wide.

With parity maintained by that 43rd minute intervention, Southend then immediately attacked and took the lead. Oli Coker swung a left-wing free-kick from 25 yards out in between the Peterborough defence and the goalkeeper and Kenny Coker was on hand to stab home from close-range.

The second half began with Jones testing Purcell following a pass from Ishola, the young custodian making an important sprawling stop before Connor Peters volleyed over a Luke Harris set-piece. Peters then met another dead-ball delivery with a towering header that Purcell superbly turned around the post before O’Connell nodded the resultant corner wide.

With less than a quarter-of-an-hour remaining, Blues almost added a second, only for Peters to arrive out of nowhere to clear off the goal-line. Adedoja was the unfortunate attacker, having sent a low finish beneath the goalkeeper in a one-on-one situation.

Within a couple of minutes, Peterborough had equalised. Again, Purcell made the initial stop, this time with his legs, to thwart Rod McGlinchey, but O’Connell was on hand to tap in the rebound and leave the result on a knife-edge.

There were chances at either end in a tense denouement. Substitute Nascimento saw his shot smothered by Purcell before setting up Nicky Gyimah, who failed to keep his left-footed attempt down. At the opposite end Damaray Anyadike, hat-trick hero against the Cobblers, fired over after darting into penalty area and opening his body up for the shot.

A point would have been enough to have kept Southend in the hunt for their first EFL Youth Alliance South East Conference crown for 12 years, but instead Posh claimed the title with three minutes remaining when Nascimento latched onto a through-ball and lobbed Purcell with a quality finish.

“We didn’t give up, but unfortunately we couldn’t equalise,” Heath reflected. “We had a couple of set-pieces in the dying moments, and the boys kept going right to the end, but it wasn’t to be on the day.

“It was a great learning experience for the group. It was like an FA Youth Cup match in that it was about the result, and it was all about learning how to perform under pressure.

“When you get into the first-team environment, it’s about playing in front of fans and going out to get the three points, and this was a little bit like that. The best teams in the world perform at their best in the biggest games.

“The boys knew their target; they didn’t need us to tell them in the lead-up to the game. They’d seen the league table and they knew the situation. In terms of their learning, the importance of going out and performing under that pressure was the key experience from the match,” he concluded.

Blues travel to Gillingham on Saturday before rounding out the first phase of the season at home to AFC Wimbledon in their final fixture.

Southend United U18s: Finley Purcell, Jaden Crowhurst, Louie Arrowsmith, Callum Burkey, Tommy Davis, Jimmy Wallace, Damaray Anyadike, Cameron Brown, Kenny Coker (Brian Garzon, 74), Oli Coker, Tayo Adedoja.

Goal: Kenny Coker (44).