Political service does not depend on appointments, Acting Manpower Minister Tan Chuan-Jin said in a Facebook post on Saturday, and he will continue to make a difference where he can.
The young ministers are all on the same team serving the same cause and not in a competition, he added, in his first comments on the recent Cabinet reshuffle.
The former army general, who will relinquish his appointment as Senior Minister of State for National Development from Sunday, wrote: "There is a reason why we serve, and it doesn't depend on our appointment.
"I'm already blessed to have this opportunity and will continue to make a difference where I can."
He is widely seen as part of the PAP's fourth generation of leaders, all of whom entered politics in the 2011 General Election. The others are Education Minister Heng Swee Keat, Acting Minister for Culture, Community and Youth Lawrence Wong, and Acting Minister for Social and Family Development Chan Chun Sing.
From Sunday, Mr Chan will become a full minister at MSF, and Second Defence Minister.
Prime Minister Lee Hsien Loong had said on Wednesday that the changes to Mr Tan's appointments was so he could "concentrate on his responsibility" at the Manpower Ministry as "taking on two portfolios is too heavy".
Mr Tan, in a response to comments which mentioned competition among future leaders or a "promotion race" on his Facebook page, said on Saturday:
"Appreciate your thoughts. But it is not a competition. We are all on the same team and are friends and colleagues serving the same cause."