What must Juan and Elton do?

Goodday, while the chosen 10,13 are excellent players, what else must Juan and Elton do to earn a real run in the squad? After Goosen's unfortunate injury, I'm sure Elton was full of anticipation, and now? Juan had an excellent game in CC final, both in defence and attack. Remember what happen Wayne Julies (chance was rather give to  an outsider De Wet Barry)?, and Wayne ended playing less than 20 tests over a 10 year period. Wayne was unable  to fulfill his full potential, I am afraid same will happen to Juan.