Exeter director of rugby Rob Baxter says the club could not afford to keep Argentina winger Santiago Cordero.
The 25-year-old, who has scored six tries this season, will join French club Bordeaux in the summer.
Baxter says there was not enough room in the club's salary cap to keep him alongside wingers such as Jack Nowell, Alex Cuthbert and Olly Woodburn.
"There are some realities financially to the squads that you can put together in the Premiership," Baxter said.
"It's something that people and supporters probably need to get their heads around a little bit is that we haven't got an endless salary cap, there isn't a bucket there that we're not using that everyone else is filling up."
Cordero has been at Exeter for a season-and-a-half, initially coming in as cover for six months due to injuries.
But his pace and try-scoring abilities have made him a favourite with the home crowd, and he has been a main focus of the Exeter attack in recent months with injuries to Woodburn and British and Irish Lions wingers Nowell and Cuthbert.
"Santi's been fantastic for us, he's done better than we could have ever hoped for him to do," Baxter told BBC Sport.
"But we've got other players there, we can't just keep on offering extra contracts to everybody and keep strengthening the other places in the squad."
Exeter were the only top-flight club to make a profit last season, but under rules agreed until the end of the 2019-20 season Premiership clubs are only allowed to spend £7m on players wages, as well as have two squad members whose salaries are outside the cap.
And while Baxter approves of the cap, he feels there are ways it could be improved going forward.
"I like the salary cap and the quality of competition it creates in the Premiership," the 47-year-old added.
"I know ourselves and Saracens have created a gap, but if you look at our results and Saracens' results there is a bit of an 'anybody can beat anybody on their day' feel about the Premiership.
"On the flip side of that it does feel a bit odd that in France they now link it to your income so there is some kind of a cap.
"In this country whether you're losing millions of pounds or making millions of pounds the salary cap doesn't change.
"There's some things there that probably need sorting out, but on the whole everybody who enters this competition knows exactly what the rules are and you work to them, that's what makes the competition what it is."