Exeter Chiefs director of rugby Rob Baxter has suggested an increase in England match fees could help prevent top players leaving the Premiership.
It comes as Premiership clubs face a reduced salary cap of £5m, meaning English sides cannot always compete with the wages other teams can offer.
Players can only play for England if they play in the Premiership.
"I suppose with a £5m cap, all of a sudden the attraction of staying in England, because you can play international rugby, lessens a little bit because of the differential in the figures," Baxter told BBC Sport.
"There is another argument we could sit here and say, which is if England paid them more per game. That would cause some debate in itself because obviously England players are pretty well paid compared to some other nations, but that's another way of bridging the gap.
"What a player does is they add up the whole package. What's happening now, the disparity between the cap, even with international match fees on top, is still pretty big.
"It's a challenge and it's one of those things that's going to happen for a little bit. We've just got to decide to get on with it as best we can."
After the Covid-19 pandemic, Premiership clubs agreed to cut the salary cap from £6.4m to £5m from the 2021-22 season through to the 2023-24 campaign.
Baxter said he cannot guarantee that Simmonds - who had a clause to opt out of the final year of his deal at Sandy Park - will be the only international player leaving Exeter next summer.
The Chiefs lost England and British and Irish Lions lock Jonny Hill to Sale last summer, while homegrown Scotland forward Sam Skinner moved to Edinburgh.
"If someone turns around and identifies one of our other players and it's another French club, similarly it's going to be difficult to match it," said Baxter.
"An outcome of us winning the Champions Cup and winning some trophies is the players you've got here can become individual targets.
"We can't collectively make all our players the highest-paid players in their position in the Premiership, you can't do that.
"So when other clubs start talking about figures that are making them the highest paid, you can't do that for everybody. That's just a management thing and we've just got to get on with it."