Arsenal manager Arsene Wenger believes that Southampton could have easily added a European trophy to their cabinet if they had managed to retain their players.
Rickie Lambert, Adam Lallana, Dejan Lovren, Luke Shaw and Calum Chambers followed Mauricuo Pochettino towards the exit to join rival Premier League clubs.
The Saints academy has also produced talents like Gareth Bale, Theo Walcott and Alex Oxlade-Chamberlain.
The north London club have acquired Chambers' s services and have previously raided Southampton for Walcott and Oxlade-Chamberlain.
However, Wenger hailed the effort the south coast club's management and scouting team put into their academy but feels that the contemporary competitive era does not favour them.
"I respect first of all the quality of work they have done because you look at Southampton and you think the team they had last year, plus Walcott, Oxlade-Chamberlain, plus Gareth Bale who come out from there - they could have won the European Cup had they managed to keep everybody together," Wenger told Arsenal's official website.
"But unfortunately the modern game has changed and the smaller clubs with less potential are not in a position anymore to keep their players."
New manager Ronald Koeman has over £90m to invest and rebuild his squad following the departure of the five players.
Wenger wonders how his Dutch counterpart will respond to the situation and bring in players who can help Southampton break into the top six next season.
"It will be interesting to see how they get over what happened to them because they got a lot of income and they have shown in the past they are very clever in scouting. It will be very interesting next season to see how they manage what happened to them," the 64-year-old added.
Meanwhile, the Gunners are due to play Monaco in their second fixture of the 2014 Emirates Cup on Sunday.The hosts thrashed Benfica 5-1 in their opening game, as Yaya Sanogo scored four while Joel Campbell struck one.
Summer signing Alexis Sanchez was given only 17 minutes to mark his debut appearance for Arsenal. Wenger also revealed that the Chilean international is not fully fit but will feature for one half against the Ligue 1 giants.
"He is not fit yet, but he has shown through some runs he will be very dangerous. He can play on the flanks and through the middle. [On Sunday] I will certainly play him on the flank for 45 minutes. He is not fit yet, but in one week he should be much better," the French manager concluded.