(Eugene, OR)  --  Former Oregon Ducks quarterback Marcus Mariota made his case for being the top overall selection in this month's NFL Draft.  Mariota worked out privately for Tampa Bay in Eugene Tuesday, and the Buccaneers' staff came away impressed.  The Heisman Trophy winner threw about 45 passes in a fast-paced session that allowed Mariota to show off his arm strength and footwork.  Tampa Bay brass, including head coach Lovie Smith were on hand to assess and evaluate Mariota.