But L.A. is trying to remain under the luxury tax until 2022, is reportedly reluctant to give Harper a long-term deal, and remains focused on making its lefty-heavy lineup more balanced, so another trade might be the answer.
Here are three players the Dodgers may want to make a deal for instead of handing a historic contract to free agency's golden boy.
The Dodgers are rather thin at catcher, and while re-signing Yasmani Grandal may still be in the cards, baseball's best backstop is available.
Trade discussions for Realmuto have cooled since the winter meetings, but Los Angeles' front office would consider moving at least two of its top prospects in Keibert Ruiz, Will Smith, or Dustin May in a trade for Realmuto, according to a report.
Following Friday's blockbuster, the Dodgers acknowledged to Bob Nightengale of USA TODAY Sports that they're "badly in need" of a right-handed bat.
Los Angeles' packed outfield might make it difficult to accommodate Castellanos, but Cody Bellinger, Enrique Hernandez, and Chris Taylor can play a number of positions around the diamond, and Castellanos could also spell Justin Turner at third if needed.
The 26-year-old Tigers slugger posted career highs in hits (185), doubles (46), and OPS (.854) last season, and was more effective at the plate than Realmuto, Nolan Arenado, and Giancarlo Stanton based on Fangraphs' offense metric.
The Dodgers' starting pitching is already very good. Their 3.19 ERA was tops in the NL last season and a full year of Walker Buehler should only help matters.
However, two consecutive World Series losses and walk years approaching for both Rich Hill and Hyun-Jin Ryu might be enough for the Dodgers to beef up their rotation by adding two-time Cy Young winner Kluber, who is under club control for three seasons.
Since 2014, no pitcher has accrued more fWAR than Kluber's 31.
Los Angeles has reportedly been involved in discussions for more than a month with the Cleveland Indians about Kluber, and they apparently re-engaged them about a potential deal following the recent blockbuster.
Cleveland is motivated to move Kluber, and a chance to acquire highly touted outfield prospect Alex Verdugo - who the Dodgers are willing to trade in a potential swap - might be enough for them to pull the trigger on a deal.