Double checked. he needs indeed 21 training points to lvl 70 (6 more points to lvl 69).
Your best bet imo is to use whole season and sell on the last season day ... you will get your money back plus a nice little profit.
I dont suggest you keep him, at his age he will gain those points really hard in a season's time, even if he manages not to get any injury (hes old with a high injury risk) and win another star, he ll lose it next season.