I am 100% sure that nadal would have played all the big clay court tournaments and would have broken down by RG. Now he is forced to play at most 2 tournaments before RG where most probably he will go out early in one of them them. At this stage a schedule like 2020 where he played only Rome and RG should be enough. Grand Slams allow you to come into form via match practice in early rounds against relatively weaker opponents so I think we have nothing much to worry.