There was a classic example of Germany v Austria in a World Cup a good while ago where they played out a convenient draw so that both teams would progress. One result of that was that all final group game matches in big tournaments are now played simultaneously to try to avoid such convenient results.
So, I think that that has eliminated the situation you refer to in football, or at least attempted to address it. There is also the issue of teams fielding vastly weaker sides than they could field in Carling (League) Cup matches, although that particular tournament now attracts UEFA League qualification, so it's not such a lame duck competition as before. Even then, teams have been fined for being over-blatant in that respect.