We are looking at the best-case scenario for some mid-round draft picks of the San Francisco 49ers.Player: Bruce EllingtonPosition: WRRound: 4Earliest he could have big role: Week 1Why is there an opportunity? Ellington gives the 49ers something they have been missing -- blazing speed. He will fill the role of the deep threat. They've been sorely missing that piece.Who is in his way? No one, really. The 49ers have plenty of receiving options.