HOUSTON ASTROS — Optioned RHP Jake Buchanan, C Max Stassi and 3B Matt Dominguez to minor league camp. Agreed to terms with RHP Jared Burton on a minor league contract. OAKLAND ATHLETICS — Optioned RHP Chris Bassitt and OF Alex Hassan to Nashville (PCL). SAN FRANCISCO GIANTS — Reassigned RHP Curtis Partch to minor league camp. BASKETBALLNational Basketball AssociationNEW YORK KNICKS — Signed G Ricky Ledo to a second 10-day contract. American Hockey LeagueBRIDGEPORT SOUND TIGERS — Signed F Colin Markison to an amateur tryout agreement.