Light heavyweight star Glen Johnson says Joe Calzaghe has taken an easy option in targeting Roy Jones Jr.
Johnson is one of only two men to defeat Roy Jones Jr
Johnson and Antonio Tarver are the only men to have beaten all-time great Jones, but the US-based Jamaican, 37, says Jones is now "past it".
Johnson says Calzaghe is right to want Jones as the biggest name, but that the Welshman will need to face him and Tarver to establish his credentials.
"Roy isn't a major player in this division any more," said Johnson.
Calzaghe's promoter Frank Warren is working towards bringing Jones to Cardiff's Millennium Stadium on 8 July.
The American is keen on the fight, and has said he is prepared to come down to super middleweight to challenge for Calzaghe's WBO and IBF belts.
But a clash at light heavyweight seems more likely, a move up to 175lbs that Calzaghe has long talked about.
"Roy is an easy step up for Joe, a marketing tool, but if he wants to fight someone with prestige and credibility then it would be me or Tarver," said Johnson.
Johnson beat Jones after missing out on Calzaghe
"Roy is the biggest name despite being past it so Joe would pocket loads of cash, if I was him it would be the fight I'd try for.
"Joe must be quick because I think Roy will probably retire very soon."
Calzaghe was due to face Johnson in June 2004, but the Welshman withdrew with a back injury - to the fury of the Jamaican.
Instead, Johnson went on to meet Jones, and made his name with a shock ninth-round knock out.
Johnson has since won and lost against Tarver and - although neither man currently holds a major title - the two are considered the best fighters in the light heavyweight division.