"Doug has decided to make his commitment to San Jose State," said his father John. "He is excited to be a Spartan."
Blacksill became the second Central California prospect to commit to the Spartans this week, joining Visalia (Calif.) Redwood receiver K.C. Pearce.
The 6-5, 260-pound Blacksill and his Liberty teammates are 3-2 in 2010.
He was a First Team All-Southeast Yosemite League pick and Second Team All-Area selection in 2009.