Donaldson, 34, had a great bounce-back season for Atlanta in 2019, and was generally seen as getting a deal in the 3 year, $75 million range. With Anthony Rendon off the board, however, Donaldson’s market has apparently increased to the point he is asking for — and, it sounds like, is likely to get — a four year deal.
If the Rangers miss out on both Rendon and Donaldson, that would be a pretty major miss for a team that has a gaping hole at third base and whose top positional priority was getting a top notch third baseman who could hit righty in the middle of the order — a role either Rendon or Donaldson would fill quite well.
The other two big time third basemen who have been talked about as being available are Kris Bryant, who has either one or two years before he hits free agency (depending on how the arbitrator rules on his pending grievance), and who will cost a significant amount in talent given up, and Nolan Arenado, who signed a big extension with Colorado a year ago, has an opt out, and who the Rockies will likely want a lot for. Neither of them seems like legitimate options for the Rangers.
Other external third base solutions include 2019 New York Mets Todd Frazier, who is a free agent, and Jed Lowrie, who missed just about all of 2019 due to injury, and whose contract, which has $10 million remaining for 2020, the Mets are wanting to move.
That being said...if the Rangers are out on Donaldson after missing on Rendon, and after missing on Zack Wheeler, that means the Rangers are moving on to Plan...E? Plan F? for the offseason.