1 month rest is enough for pro athlete, according to professional fitness coach (basketball). Games take their toll. You think one should be able to rest after let's say wednesday's game for a day and play normal in saturday...and pro athlete can. but it takes tall after a while, it just build up in your muscles. Unfortunately we don't have fit Neymar or ban free Suarez, hope that will not rush Messi back. If we had thoose 2 I would say give Messi one month, he doesn't need to start games at the beginning of the season. Then pass him through fitness training and normal team training and then put him in play....but if there are problems after that then there is something wrong.