Best to train after your last match of the day!, if you have multiple matches that day then dont train at all or just use stretching as your players will have gained loads by the matches and they will be low on condition and so be more injury prone!. You must also look when your next day match is, because if you say have a match late on in the day and your next match the following day is say 4-5 hours later then you deffinatly DONT want to train unless your prepared to use lots of boosters to replenish there condition!. If you are a token buyer and are prepared to invest in loads of booster packs to power train then you hard train 1 player every half hour!, other than that I personally train 1 or 2 times a day, 1 if im hard training and 2 if I do cardio and stretching buy ONLY if I have the ONE game!!!.