The Saints announced on Wednesday that club great Riewoldt would lead the team for an eighth season in 2013.
But Riewoldt told SEN radio on Thursday he would have been happy to step down for Goddard if the star utility had recommitted to St Kilda.
"I thought if BJ (Goddard) was still at the club that it would have been him this year, and I was more than happy for that to occur and for anyone else to step into the role," Riewoldt said.
The respective No. 1 picks in the 2000 and 2002 Drafts, Riewoldt and Goddard played together for 10 seasons at St Kilda, and were key members of the Saints' 2009 and 2010 Grand Final teams that went so close to delivering the club its second premiership.
They are also close friends off the field, with Goddard a groomsman at Riewoldt's wedding in Texas last October.
Riewoldt said he had done his best to talk Goddard into ignoring Essendon's lucrative offer and staying at St Kilda.
"I certainly wanted him to stay a St Kilda player, but at the end of the day it was his decision and I respect the decision he's made," Riewoldt said.
"There were a lot of things to consider for him and in the end he's made his decision and I'm comfortable with it."
Riewoldt is the Saints' second longest-serving captain on 139 games, but is unlikely to catch Danny Frawley, who led the Saints in 177 games from 1987-95.
Nick Bowen is a reporter with AFL Media. Follow him on Twitter: @AFL_Nick