Might be stretching the budget but it would be really cool to have a hyperbolic time chamber like in Dragonball Z. Would give the team a huge advantage in terms of training. Instead of getting say 10-15 hours of training per week like most professional teams might (at least this is the amount of training a pro soccer team does), you'd be getting about 4-6 months worth of training in the same time. Imagine how quickly rookies would develop in that time! Imagine how it could be used for resting veterans between games to prolong their careers!

Probably wouldn't be within budget though, sadly. So I guess the real answer is to focus on improving equipment and facilities for injury recovery and rehab. Things like that. The sport has a pretty high injury rate after all, so it feels like reducing the impact of that would be a wise way to spend the money.