Matthew Rees wants defence coach Shaun Edwards to continue as a member of Wales' backroom team.
Hooker Rees, who missed the World Cup because of injury, says Edwards has played an important role.
"Shaun works well with Gats [head coach Warren Gatland] and it's important to keep them together," said Rees.
Edwards joined Gatland's backroom team in 2008 with Wasps agreeing to the former Great Britain rugby league player being involved with Wales during tournaments and tours.
Welsh Rugby Union group chief executive Roger Lewis indicated that they were keen to retain Edwards, but admitted the former Wigan player's situation was complicated.
Wales conceded six tries in seven tournament encounters and scored 29 with only opening opponents South Africa outscoring them on touchdowns, two-one in the Springboks' 17-16 Pool D win.
Wales' try tally in included 12 against Namibia and nine against Fiji.
They finished one-all in the 17-10 win over Samoa and two-all in the 21-18 bronze medal defeat by Australia after outscoring France one-nil on tries in the semi-finals and beating Ireland three-tries-to-one.
Scarlets hooker Rees, whose neck surgery ended his hopes of leading Wales in New Zealand, says retaining Edwards is crucial if Wales are to build on the progress made during the World Cup.
"He's very important," Rees told BBC Wales' Scrum V.
"Shaun has brought in a structure which works well for us. To win competitions you've got to have a defence.
"Shaun stated as soon as he came in [that] if you want to win trophies defence is going to be key to that.
"I think that was shown in the first year he was here in 2008 and I think the defence has been outstanding in this tournament as well."
"Obviously I went to the two camps in Poland and you could just see it building," said Rees.
"We had three tough games and you could see the way the boys were playing and training that they were on the verge of something special.
"The biggest thing for me is the youngsters have come through and done a great job for us. Hopefully they will be there for many more years.
"We're only going to lose one or two players over the next year with obviously Shane [Williams] probably retiring and maybe Steve [Stephen Jones].
"Other than that [the] squad is going to be together for a long time."