Southampton manager Ronald Koeman says some players at rival clubs are motivated by money.
Koeman, whose side face Liverpool in the Premier League on Sunday, has acknowledged that it is difficult for him to keep hold of players.
"A reason to move is not always for the player to do [with] football," the Southampton manager said.
"Maybe it's about money and we can't pay salaries like the big teams pay. It's always less here."
Koeman said that Southampton's players are motivated by football rather than financial reward.
"If you stay here, you stay for different reasons," the Southampton manager said.
"You stay for the fact you are more sure that you play every weekend."
Southampton lost manager Mauricio Pochettino to Tottenham in May before five key players also left during the summer. Midfielder Lallana, defender Lovren and striker Lambert moved to Liverpool, while left-back Luke Shaw signed for Manchester United and Calum Chambers joined Arsenal.
Yet despite being made relegation favourites by a number of bookmakers, the club are fifth in the Premier League.
Koeman, who became Saints boss in June, says he asked Chambers not to go to the Gunners.
"I said to Chambers: 'Really, I don't think it's a good moment to change and to go to Arsenal because I think you need to develop yourself much more,'" he said.
"Normally, you will play here much more than you will play at Arsenal, but finally it's always the decision of the player."
Southampton can go third if they beat Liverpool at St Mary's Stadium and Koeman maintains it is "a possibility" that his team can finish in the top four.
"But it is a good possibility for other teams as well," said the manager.
"These kind of teams are never struggling a whole season, they're always coming back. They have real quality in the team and numbers in the team to finish in a good position in the table."