Cross one Plan B off the board.

Infielder Mike Moustakas, coming off an All-Star season in Milwaukee, signed a four-year, $64 million deal with the Reds Monday. Moustakas was among the Braves' options at third base should free agent Josh Donaldson depart.

Moustakas, 31, hit .254 with 35 homers and 87 RBIs. The Braves have been adamant about their hope to retain Donaldson, but Moustakas was among the players they considered an alternative (the degree of the Braves’ interest was unclear).

» ALSO: Braves non-tender Charlie Culberson

Of course, the terms of his contract certainly exceed that of any backup plan. The Reds vowed spending and hope to vault themselves into playoff contention after years of wallowing in mediocrity. They made a major commitment to Moustakas as their second baseman.

Donaldson’s situation was likely affected by Moustakas’ signing. It’s one less alternative on the third-base market, where Anthony Rendon and Donaldson stand head-and-shoulders above the pack. The Braves, Rangers, Phillies, Dodgers, Nationals and others have reportedly shown interest in adding a third baseman.

In other words, when the music stops, several teams will be without a chair. The Braves probably won’t reel in Rendon, so should Donaldson sign elsewhere, the franchise could be better off turning to other teams in search of a more known quantity at third.

The Braves have already been big spenders a month into the winter. They signed reliever Will Smith and retained relievers Chris Martin and Darren O'Day. The team non-tendered three position players Monday, including beloved utilityman Charlie Culberson, so it will certainly explore depth options on the market as well.

For now, Johan Camargo is penciled in as the team’s starting third baseman. Emphasis on “for now.”