Eisenhower was George Marshall’s choice to command Overlord [when Roosevelt wouldn’t give the job to Marshall]. FDR went along with Marshall’s choice.
Marshall recommended. Roosevelt reviewed the recommendation, met with Eisenhower to evaluate him and decided it was a good choice.
Eisenhower demonstrated on a number of occasions that he was Roosevelt's man. His decision in 1945 not to contest the Russians for Berlin comes to mind, as does his refusal to support Hungarian freedom fighters in 1956.
Indeed, now that I'm thinking about it, ask yourself this question: who was the greater anti-Communist -- Democrat President Truman or Republican President Eisenhower?
Sort of makes you think... was Eisenhower more of a Roosevelt-man than Truman?