The phrase "his indispensable" is not correct as it is incomplete and lacks a noun to clarify what is indispensable.
You can use it when referring to something that is essential or necessary for someone, but it needs to be part of a complete thought.
Example: "His indispensable skills in negotiation helped the team secure the deal."
Alternatives: "his essential" or "his crucial".
Sisulu became his indispensable political mentor, and introduced him to his cousin, Evelyn, whom he married.
By the way, a conscientious running accounting of Palindrones is being maintained by Andrew Sullivan on his indispensable blog.
As K. K. Collins discovered in compiling his indispensable volume, "George Eliot, Interviews and Recollections," many of those who encountered George Eliot felt moved to describe her looks.
He reorganized and strengthened his armies with the competent aid of Arakcheyev, the instructor from Gatchina who had become his indispensable colleague.
During John Adams's overseas stint, John Quincy had been his indispensable second, and later earned appointments to crucial diplomatic posts of his own.
As Hollis Alpert wrote in his indispensable study "The Life and Times of Porgy and Bess," Heyward now "foresaw Negroes breaking down the bastions traditionally reserved for whites".
His second, indispensable virtue is his feeling for the pas de deux.
He also considers his bright orange, multi-pocket field vest and the buck knife that hangs from his belt indispensable items that support his field 'persona', which he says helps him to lead students through dicey situations.
In his latest indispensable oral history, adapted from interviews he conducted for his radio show on Chicago's WFMT, Terkel talks with more than 40 legends of jazz, blues, folk and classical music.
Ryan has lost one of his most indispensable players — he once called Revis one of the top three cornerbacks in N.F.L. history — and his job could be in jeopardy if the Jets miss the playoffs for a third straight season.
That was comforting news to Manager Joe Torre because Posada is one of his most indispensable players.
