The most popular idea here is that stamina and free thrown training is only worthwhile on weeks that you have 2 games. This most likely should only be during the all-star week and at the end of the season if you fail to make the playoffs.
Unless stamina is really low, you can always train in 2 positions for that week. However, stamina does keep skill levels higher for longer. So it all depends on whats best for your team at that time. Also, stamina pop once every 2 weeks, possibly better off training 2 positions unless you are worried about a drop in stamina or have important matches coming up at the end of season.