Washington Nationals plane

Does anyone have the tail # for the washington Nationals plane?

I believe its BSK699, Miami Air International 737-400. flightaware.com/live/flight/BSK699/history

It left Dulles Monday evening enroute to San Diego, apparently stopping at PHX to refuel, or something. I saw it sitting across the runway Wednesday at SAN, but couldn’t catch a tail number from a UAL window.

Should be headed for PHX sometime this evening [Thurs. 5-29].

And, it went off to PHX about 530pm PDT. BSK699.