Billy Slater of the Storm attempts to catch the ball.

Fall guy: Billy Slater is in doubt for Melbourne's clash against South Sydney and a face-off with their fullback Greg Inglis. Photo: Getty Images

Greg Inglis says he'd happily pay to watch Billy Slater play but the sight of his rival fullback in a moon boot means the paying public might not see the Melbourne star in action on Saturday night.

Inglis and Slater are slated to go head to head in the top-of-the-table clash between South Sydney and the Storm at ANZ Stadium. The encounter between the NRL's only undefeated teams is shaping as one of the best of the season and perhaps a preview of what is to come in September. Or perhaps October.

While there are any number of marquee match-ups - including Adam Reynolds against fellow halfback Cooper Cronk, rakes Issac Luke and Cameron Smith, and the coaching duel between Craig Bellamy and Michael Maguire - the most salivating is the prospect of Inglis taking on Slater and his former club.

Slater is in a moon boot after suffering a foot injury in the 26-12 win over Wests Tigers on Monday. However, officials are hopeful he will recover in time for a game that could attract more than 25,000 fans. ''We all know and respect what Billy Slater can do … as a football fan, I'd pay just to watch Billy Slater play,'' Inglis told the ANZ Stadium website.

''I've played with him [for Melbourne, Queensland and Australia] and against him [for the Rabbitohs] and I can tell you it's much easier playing with him.''

Inglis rarely played fullback at the Storm, starting mainly at centre followed by a stint at pivot. Maguire's decision to give him the No.1 jersey has proved a masterstroke, although Inglis admits he is still learning the art. ''Personally, I know I have a lot of improvement left in me as a player, and especially in the No.1 jumper,'' he said.

Bellamy said a decision would be made on Slater's availability depending on how he pulled up after Friday's training session. ''We're not quite sure how bad the problem is at the moment, but we'll see how he pulls up and hopefully he trains on Friday and we go from there,'' Bellamy said. ''He's certainly causing a little bit of angst at the moment, I must say, but if there's any possibility of him being there, he'll be there. [But] we certainly won't be taking any chances with him.''

Slater will be keen to prove his fitness to ensure his availability for Australia's Test against New Zealand next Friday. Inglis will be the man to replace him should the injury be more serious than first thought. Both players have been in outstanding form this year and are a big reason for the 5-0 win-loss record for their respective teams. If anything, Inglis has been superior statistically, leading in average metres run per game (187m to 132m), tackle breaks (35-16) and errors (2-5). However, Slater is shading him in tries scored (5-2), offloads (4-1) and line breaks (6-5).

By scoring against the Warriors last weekend, Inglis brought up the 100th try of his glittering career. ''That was a nice milestone,'' he said. ''I didn't realise that until someone mentioned it to me in the sheds. Hopefully there is more to come.''

While the Rabbitohs have stamped themselves as a genuine threat, Inglis believes further improvement is necessary to challenge the Storm.

With AAP