The England international was omitted from the squad to face Schalke in the Champions League on Wednesday evening, and is now struggling to force his way back into contention for the weekend visit of former club Manchester City.
"We have 25 players in the squad, most are international players, and we are allowed only to play 11 and five from the bench," said Grant.
"Every game we play there are five or six international players, good players, who are not in the squad.
"It's not personal against anyone. I'm thinking about the team. Shaun is a professional. He wants to play of course, he wants to be in the squad. He's ready for the next games.
"I want players to be happy at the end of the year. They will look back and say I gave my contribution to my team. Sometimes during the season they will not be happy if they are not playing. But they need to be ready for each game we need them in the future."