Steffen Johnson, a 14-year veteran of Winston & Strawn, has left the partnership, according to the firm’s website and court documents.

Bloomberg reported that Johnson, based in Washington, D.C., had joined Winston Sonsini Goodrich & Rosati. A Wilson Sonsini spokesperson declined to confirm the report or to comment, but Johnson’s name appeared Monday evening on an archived version of the Silicon Valley-based firm’s lawyer directory.

Steffen Johnson, formerly of Winston & Strawn (Courtesy photo)

Johnson, who was a co-leader of Winston’s nationwide appellate and critical motions practice, has argued and briefed several cases before the U.S. Supreme Court. His clients have included New England Patriots quarterback Tom Brady in the Deflategate controversy and Hikma Pharmaceuticals and Teva Pharmaceuticals in patent cases before the Supreme Court.

Other clients have included Abbott Laboratories, the American Petroleum Institute and the Republic of Ecuador.

One of Johnson’s former Winston & Strawn partners noted his departure from the firm in a July motion filed in a D.C. federal court lawsuit in which Johnson was defending the executive director of the National Football League Players Association.

Before joining Chicago-based Winston in 2015, Johnson served in the Department of Justice’s Office of Legal Counsel during President George W. Bush’s administration, as a lecturer at University of Chicago Law School and as an associate in Mayer Brown’s Supreme Court practice.

Johnson could not immediately be reached for comment.