Fulham will sign midfielder Jimmy Bullard from Wigan when the season ends after agreeing a £2.5million fee with the Latics.
The 27-year-old Londoner will join Fulham on a four-year deal on May 8, after the final match of the campaign.
Bullard - who joined Wigan for £275,000 in 2003 - travelled to London on Thursday to undergo a medical.
Fulham's bid was enough to trigger an escape clause in Bullard's contract, a situation reminiscent of Nathan Ellington's departure to West Brom last summer when the Baggies were informed of a £3million sale clause in the striker's contract.
"His agent alerted clubs that Jimmy has a clause in his contract that allows him to leave for a certain price," said Jewell. "We have to - by law - tell Jimmy if a club comes in for him, and he wanted to speak to Fulham."
He added: "If a player decides to leave it is best if he does. I have always said there's no point in keeping unhappy players, or at least players who want to move.
"The timing is not the best but I understand that Fulham wanted to move quickly and not lose their man."
Having anticipated protracted negotiations between the clubs on how Fulham would pay the transfer fee, Jewell did not expect the deal to go through so quickly.
But, while he was disappointed to see Bullard go, he is adamant his departure does not signal the break up of his current squad - instead, it is merely the start of the club rebuilding and getting stronger.
"There are only three other players I've been gutted to see leave - Arjan de Zeeuw, Nathan Ellington and Jason de Vos," said Jewell.
"But we got over them, and we became stronger, and we will get over Jimmy as well. Life will go on without Jimmy.
"I just hope the supporters don't think we're starting to sell the family jewels because we will try to improve the team for next season.
"If there are any other departures it will be because a player is unhappy, and none of the other players have intimated that to me.
"If they are, we will find the right club and get the right deal, and then they can go. I'm not going to go down on bended knee begging players to stay.
"If we had decided to match Fulham's wage offer then maybe we could have kept hold of him but I didn't want to set a dangerous precedent and be held to ransom.
"That would be extremely unhealthy."
Jewell defended the decision to allow the release clause to be included in Bullard's contract as the former Peterborough midfielder was content to leave on a Bosman without it.
The Wigan manager added: "I don't blame Jimmy for wanting to look after his family because you are only one tackle away from your career being over."