Jones, 31, said: "It's going to be a competitive tour from a selection perspective and the fly-half position will be absolutely no different. Ronan is playing very well and he is a quality player. It will be a big challenge to try and oust him.
"But once the tour starts it's all about trying to focus on your own game because selection is out of your control. There are only two specialist fly-halves going and it will be interesting to see what the coaches plans are.
"They will want to build and develop a game plan and as an outside-half it's important you become comfortable and accustomed with that because you have to help implement it on the field.
"That will be the first challenge and then you have to try and bring your own stamp on things. Hopefully that will be enough for me."
Jones will start on the bench at Musgrave Park hoping to renew his epic battle with Ireland Grand Slam hero O'Gara following last month's thrilling Six Nations climax in Cardiff. The pair were also rivals on the humiliating whitewash three-Test tour to New Zealand in 2005.
Jones said: "I'm delighted to have been selected for my second tour and I know it will be a challenging trip. We've a few domestic games left and I've got a job to do with the Scarlets. The only thing you can do is prepare to the best of your ability.
"But we can beat South Africa. It's a massive challenge and doesn't get much harder than beating the world champions in their own backyard. It's a Lions squad full of talent and ability. Hopefully we can do the Lions shirt justice."
Munster: P Warwick; D Howlett, K Earls, L Mafi, I Dowling; R O'Gara, T O'Leary; M Horan, J Flannery, J Hayes, D O'Callaghan, M O'Driscoll (capt), A Quinlan, D Leamy, D Wallace.
Replacements: D Fogarty, T Buckley, D Ryan, N Ronan, P Stringer, B Murphy, D Hurley.
Scarlets: D Evans; M Jones (capt), R Higgitt, J Davies, L Williams; R Priestland, M Roberts; I Thomas, M Schwalger, S Roberts, V Cooper, D Day, J Turnbull, D Lyons, R McCusker.
Replacements: P John, M Rees, A Shingler, J Edwards, G Cattle, S Jones, C Thomas.