That was the problem Roma was having since last season, the need of new players and that issue was covered under the rug because they thought that replacing Mourinho is the best option, thinking that he does not know what he is doing anymore. De Rossi came in and the problem is still lying there.
If Roma fails to buy players to support De Rossi, they will have a poor result next season and the management will still go ahead and sack De Rossi while the problem is still lying there. Is it that they don't have the money to buy players but only to buy coaches or what. Roma needs to wake up and do the needful if the have winning the trophy in mind next season.
De Rossi won't be able to make AS Roma better if the management doesn't support De Rossi in bringing in new players, especially since every coach wants players who match his coaching style and indeed since De Rossi managed Roma he has only continued on what was built by Jose Mourinho, not from the squad. what De Rossi wanted.
Regarding the big or small amount of money that Roma management has prepared to buy players, it has to be done and indeed De Rossi also has to understand that Roma is not a team that has the financial strength to buy lots of expensive quality players.