Donaldson could be a cost-effective replacement for Anthony Rendon in Washington. Rendon, who's also a free agent, is likely to command the largest contract for a position player this offseason.
After inking a one-year deal worth $23 million with the Atlanta Braves last offseason, Donaldson hit .259/.379/.521 with 37 home runs, 33 doubles, and 94 RBIs for the National League East champions.
His 4.9 WAR ranked eighth among MLB third basemen, and his 132 wRC+ was tied for seventh-best at the position, according to FanGraphs.
The 2015 American League MVP also played solid defensively. He finished as an NL Gold Glove finalist at third base after recording 15 defensive runs saved and a .969 fielding percentage.