Ronald Koeman believes his Southampton players understand the club's decision to sell its top talents and has vowed to bring in replacements who are of equal quality or better than those who have left.
The Saints have already let striker Rickie Lambert and captain Adam Lallana join Liverpool while England left-back Luke Shaw was allowed to leave for Manchester United.
Deals for all three players had been agreed before Koeman took the job at St Mary's but the Dutchman insists the departures will not affect the morale of his squad.
"They know that's the story in football, players come and go," Koeman said.
"The most important message I gave them was that we have to keep the philosophy and the ambition of the club.
"If we lose some players we will bring in players of the same quality or even better quality if that is possible.
"There is money to spend and to continue the quality and bring new players in."
Koeman carries great pedigree as a player having played for Holland and Barcelona, for whom he scored the winning goal in the 1992 European Cup final.
The Dutchman's arrival on the south coast has been overshadowed, however, by constant transfer speculation.
The former Feyenoord boss admits it is important to convince the remaining players that Southampton is a club still moving forward.
"We did that from the first day we came into the dressing room," Koeman said.
"That message is important because one thing is to say we are ambiitous, it is another thing to be ambitious and we need some more time in this pre-season to show that to the players.
"The rest of the players have to keep that ambition.
"I spoke to some of the more experienced players like Jose Fonte and Steven Davis because they have to keep that positivity in the dressing room.
"I promised them and I promise the fans that when we start the season we will have a very good team."
The summer sales may not be over yet. Defender Dejan Lovren continues to be heavily linked with a move to Liverpool while midfielder Morgan Schneiderlin is also reported to be attracting interest from the likes of Tottenham and Arsenal.
Koeman is keen to hang on to the best players that remain and believes the board have adopted a tougher stance since selling Lambert, Lallana and Shaw.
"We said 'OK this is it, we are not a selling club'. The players have contracts. We don't sell any more players and we will try keep to that," Koeman said.
"We sold three players - that's good enough. That's good enough money. Now we will keep the rest and we will continue with what we did last season.
"That's what came out of last year - a great season and they played wonderful games.
"I know Liverpool have a lot of money and they will spend that money and maybe they want to buy a player from Southampton.
"But as manager of Southampton I have to do everything to keep those players. The final decision is with the board."
One player who looks likely to stay is Jay Rodriguez, who injured his anterior cruciate ligament against Manchester City in April.
Rodriguez, who scored 17 goals in all competitions last season, has already impressed Koeman with his attitude.
"He is working very hard to come back," Koeman said.
"It is not easy at the moment when all the players are coming back and playing, it is hard and takes character.
"He has that character though and he will come back - he might be the best transfer of the winter window."
Koeman has managed eight clubs and established a reputation for an attacking style of football together with a belief in nurturing young talent.