The 73-year-old is said to be doing pretty well, but hospitalized nonetheless, according to sources.
Howe began his managerial career in 1989 as the Astros manager, remaining in the role for four seasons.
Before that, he spent a sizable part of his 11-year career in Houston, from 1976 to 1982.
Howe is arguably best known as the manager of the Oakland Athletics when the club in 2002 tied an American League record at that time of 20 consecutive victories.
Howe was portrayed by Philip Seymour Hoffman in the movie "Moneyball."