Costa has been pivotal to Chelsea's resurgence under Hiddink, netting 10 goals and contributing six assists in his last 14 appearances.
His performances have helped Chelsea go from surprise strugglers to potential Champions League contenders, with Hiddink's men now eight points adrift of the top four with 10 games left to play.
Hiddink had previously hinted that Costa may be rested against Stoke City this weekend and, while he has now said the Spain international will start, the Dutchman is keen to ensure the former Atletico Madrid forward is not overworked.
"He [Costa] won't have a full game. We monitor them with the data. He is in perfect physical shape, but we must not give him an overload in games, but he is difficult to stop," Hiddink said.
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"He wants to play every game - but I must be careful with that. Tomorrow [Saturday] he will start.
"There is always a danger of going over. If i share those figures with him, he can be rational too. Sometimes I have to put him on the leash.
"Big clubs know you must have a regular season, then in March and April everyone is queuing up, the rewards are there. You have to be there on top as a team and as a player."
Chelsea's top-four hopes have been boosted by a run of three straight league defeats for defending champions Manchester City.
However, with Manchester United, West Ham, Stoke City, Liverpool and Southampton also seemingly in the running, Hiddink knows Chelsea still have plenty of work to do.
"Others are knocking on the door, like West Ham. There are more candidates for fourth position than the teams losing recently," Hiddink added.
"Stoke are close as well. Even more reason we need a serious approach."