in bb reality it don't work that way// you when hire a player and fire him in same week or same month lateron , it goes up in the system as shady deal for profit.. high risk , low rewards. which a fine or team closure.
then you have league caps , if you haven't trained that player it goes versus tax exempt. which may put you over and 50% penalty plus the league cap penaltes.. plus shady deals in the rules.. which equals... a heavy fine and team closure.
IR / injured reserves in bb way should be money you put aside for that that cause at start of the season or mid season, to pay that player you call up for a week or 5 weeks. if want up to select 250K in IR for one 5-15k a week player then that's your call, it still money left over for future injuries cases. It would only work if you have injury to the team. it can be set as team safety net.
why spend a lot money on 1 player just sell in 5 weeks.. ??
Its about options. a injury reserve system would help.