The present disclosure describes a diversion device (500) that traps an initial flow of blood in a diversion chamber (570) of the diversion device. The diversion chamber is be defined, in part, by a housing shell (530), a housing base (540), and a filter (550). The filter is be a porous material that allows air, but not blood, to flow through it. After the diversion chamber is filled, a subsequent flow of blood is be directed into a collection vessel (504) through an internal conduit of the diversion device.
