Ospreys want to keep Wales captain Alun Wyn Jones at the region next season and believe they can help guide him through to the 2019 World Cup in Japan.
The lock's national dual contract expires at the end of this season.
Ospreys backs coach Gruff Rees believes the Welsh region can provide the best environment for the 32-year-old to make it through to a fourth World Cup.
"Alun Wyn needs to be looked after and the Ospreys will do that," said Rees.
The Ospreys have recruited Scott Williams and Aled Davies from the Scarlets for next season, but will lose Wales half-backs Rhys Webb and Dan Biggar to Toulon and Northampton respectively.
Rees, who is also leaving the region at the end of the season, believes it is vital Ospreys keep Jones, who has won 113 Wales caps and made nine British and Irish Lions Test appearances.
"It's important for the Ospreys to retain players who are at the heartbeat of what we do, historically and going forward," said Rees.
"You can see his influence over the last couple of weeks. People talk about his leadership and rightly so.
"He has come back from an international block and played some tremendous rugby in the last couple of weeks.
"That in itself is tough to replace. We just keep hoping his influence as a man will rub off on others."