The 25-year-old was capped twice on the 2009 summer tour to Canada and the USA and came on to replace Earls during the first Test defeat to New Zealand last June.
Although this Saturday's match against Fiji is a non-cap international, Cave is hoping it can be his springboard to more opportunities in the green jersey.
"There are going to be a few changes for this game and hopefully I'm one of them. I'm looking forward to getting back in green - it's been a while," he said at the team base in Carton House.
Cave burst onto the scene with the Grand Slam-winning Ireland Under-20 team in 2007, along with current Ireland squad members Earls and Cian Healy, and Ireland Sevens and Wolfhounds honours followed for him.
Earls (33 senior caps) and Healy (34) have gained much wider exposure to Test rugby in the intervening years though, and certainly a couple of untimely injuries have not helped Cave's cause.
But the Holywood, Co. Down native is hoping his solid form, allied to Ulster's resurgence as Heineken Cup runners-up and current RaboDirect PRO12 leaders, can see him catch up on the pair.
"In the early part of my career I was a victim of playing for a pretty average team. Now that the team is going a bit better, I suppose Brian has just dominated that shirt and I missed the Six Nations through injury and Keith came in and played fantastically well.
"He continued until the end of last season and he's in control of that (position) for now."
Watching his Ulster team-mates Dan Tuohy and Chris Henry play for Ireland has acted as a spur for Cave, who believes 'playing for a good team helps your international chances'.
"If you look at Ulster in the last while, and playing in those Heineken Cup games, Dan Tuohy got his chance during the summer and Chris Henry has come in at home now and performed really well. I just have to hope that I'm next on the list."
"It can be hard at times and you can definitely be jealous of someone and be happy for them at the same time. I'm a similar age to Keith and Cian and I see them now and they've got 30 caps or whatever and I think, 'Flip'.
"I'm delighted for them but I'm not going to lie and say I'd rather be on three than 30. At the same time I look at Chris last weekend, who is three years older than me, and now on three caps.
"His chance was long overdue and he took it and that really gives me inspiration - that even if I'm waiting three years that hopefully when I get in, I can take my chance like he did."
Mention the Ireland number 13 shirt and Brian O'Driscoll's name inevitably turns up. Cave concedes that the Dubliner remains 'the benchmark' for any budding international centre, admitting: "He's still probably the best going and training with him is brilliant."
The Ulster ace does not want to be viewed as a ready-made replacement for the now veteran O'Driscoll. He is fully focused on his own game and on showing what he can do on the international stage.
"I think I've put in some pretty good performances in big games with Ulster. I'd like to be given the opportunity to see what I can do at this level.
"I've been answering questions for years about Brian but I'm not looking to replace him. I'm just looking to try to play rugby as well as I can."
Cave is expected to start against the Fijians at Thomond Park, quite probably in a midfield that includes his young Ulster colleagues Luke Marshall and Paddy Jackson.
Keen to exhibit his skills in a winning performance, he added: "I'm looking forward to this weekend. It's about playing a structured game but when it gets loose and we know it will with Fiji, a lot of our backs, like myself, can capitalise on that looseness."