Nationals Roster & Staff
Transactions
| Date | Transaction |
| 09/18/09 | Seattle Mariners traded C Jamie Burke to Washington Nationals. |
| 09/18/09 | Washington Nationals placed C Jesus Flores on the 60-day disabled list. Torn right labrum. |
| 09/14/09 | Washington Nationals sent C Luke Montz outright to Syracuse Chiefs. |
| 09/10/09 | Washington Nationals claimed Jesse English off waivers from San Francisco Giants. |
| 09/10/09 | Washington Nationals designated C Luke Montz for assignment. |
| 09/08/09 | Washington Nationals selected the contract of RHP Zack Segovia from Syracuse Chiefs. |
| 09/08/09 | Washington Nationals released RHP Jorge Sosa. |
| 09/08/09 | Washington Nationals selected the contract of Logan Kensing from Syracuse Chiefs. |
| 09/08/09 | Washington Nationals recalled Ian Desmond from Syracuse Chiefs. |
| 09/08/09 | Washington Nationals recalled Ross Detwiler from Syracuse Chiefs. |
| 09/08/09 | Washington Nationals recalled Marco Estrada from Syracuse Chiefs. |
| 09/08/09 | Washington Nationals transferred LHP Scott Olsen from the 15-day disabled list to the 60-day disabled list. |
| 09/04/09 | Victor Garate roster status changed by Washington Nationals. |
| 09/04/09 | Washington Nationals activated C Jesus Flores from the 15-day disabled list. |
| 09/02/09 | Washington Nationals claimed LHP Victor Garate off waivers from Los Angeles Dodgers. |
| 09/01/09 | Luis Garcia assigned to Potomac Nationals from Washington Nationals. |