Southampton made £19m transfer splash - it ended up costing £1.9m per app | OneFootball

The signing of Guido Carrillo turned out to be a costly mistake for Southampton.

Throughout the mid-2010s, Southampton were considered among the Premier League's 'best of the rest'.

After finishing seventh, sixth and eighth across three years under Ronald Koeman and Claude Puel, Mauricio Pellegrino would take charge at St Mary's ahead of the 2017/18 campaign.

The Saints would bring in Wesley Hoedt over the summer, anticipating the departure of Virgil van Dijk, who brought in a fee of £75 million in January. Mario Lemina would also join the club, alongside Jan Bednarek.

After an under-par opening half of the season relative to expectations, Southampton would bring in Argentine striker Guido Carrillo in the winter transfer window, in a transfer splash worth £19 million. Though, as would be the case with Pellegrino's other signings, it would prove a costly mistake for the club.

£19m man proved a costly mistake for Southampton

Having scored 15 times across 65 appearances for Ligue 1 outfit Monaco, Carrillo made the switch to Southampton in search of regular game time. At the same time, the Saints required goals to lift them out of the relegation places after a torrid start to the campaign.

However, the season would never quite catch fire as hoped. Mark Hughes would replace Pellegrino in March, and Southampton would secure their Premier League safety by just three points ahead of the season, finishing above Stoke, Swansea and West Bromwich Albion.

Carrillo would make 10 appearances in a Saints shirt that term, with his only return being two assists that came against Burnley in the Premier League and West Brom in the FA Cup.

He would be dropped from Hughes' squad for the majority of the final month of the season, making the bench just once in a crucial six-pointer against Swansea.

The Argentine would join Leganes on loan over the summer, and never return to St Mary's after making just 10 appearances in all competitions - seeing the club pay £1.9 million per appearance for very little return.

Slow Southampton decline ended in relegation

The 2017/18 campaign proved to be a sign of things to come for Southampton fans. Mark Hughes would lose his job at the back end of 2018, to be replaced by Ralph Hasenhüttl.

Southampton would show some positive signs under the Austrian, with the Saints even topping the league after eight matches of the COVID-impacted 2020/21 campaign.

Though it was clear that Southampton were a very different club from the one flying high in the Premier League just four years prior. Before Hasenhüttl's dismissal in 2022, they would secure finishes of 16th, 11th, and 15th twice under his guidance.

The talent network that had seen the likes of Sadio Mané, Virgil van Dijk, Adam Lallana, and more pass through the squad at St Mary's had dried up, and the decline was well underway.

Southampton would be relegated to the Championship at the end of the 2022/23 campaign, with Ruben Selles unable to rescue the side after a dismal spell under Nathan Jones. And while the Saints would achieve promotion back to the top-flight a year later, they have never quite recovered from the initial decline that started after their European exploits and League Cup final appearance in 2017, partly down to expensive signings not doing the business.