Nationals signed infielder-outfielder Rob Mackowiak, who had been with the Padres, to a one-year contract.
An interesting decision by Mackowiak, who chose a team without a lot of playing time for him and without any real chance of contending next year. Surely there were better teams that would have liked to have had Mackowiak around as a bench player. The 31-year-old is a career .262/.334/.409 hitter, and he's still an option at third base, as well as in the outfield corners. He shouldn't play much center field or second base ever again.

Nationals signed outfielder Willie Harris, who had been with the Braves, to a one-year contract.
Harris hit .270/.349/.392 in 344 at-bats last season, but he still has a lower career OPS than Nook Logan (639 to 660). Also, while he's a fine defensive outfielder, he doesn't have Logan's Gold Glove ability in center. Plus he's the older player by a year and a half. We're not sure why Harris is worth the 40-man roster spot when Logan wasn't. He'll probably be the Nationals' fifth outfielder.
Machowiak is a good pickup because he can do it all. He is a good backup for Zimmerman if his wrist is still bothering him early in the season. Rob can also play anywhere else on the IF and play the OF too.

Nook Logan is Nook Logan. Harris had a decent year last year and Logan did not. I'm sure Harris comes cheaper too.