David Ortiz
This one is a no-brainer and shouldn’t surprise anyone. One of the greatest Red Sox players of the 2000s was also one of the best in the 2010s. David Ortiz was the Red Sox’ greatest free agent signing and in the first decade of the 2000s helped the team win two World Series, in 2004 and 2007, with his tremendous regular season production and his numerous clutch postseason hits.
He was equally as dominant in the 2010s, putting up a ,298 average, 192 home runs, 598 RBI, a .387 OBP, and an OPS of .958 between 2011 and his retirement in 2016. Along the way, Ortiz led the team both on the field and spiritually as they healed New England in the wake of the 2013 Boston Marathon bombings as he led them to their third World Series victory of the century.
He’ll forever be known for his series-changing grand slam in the eighth inning of Game Two of the ALCS, but even more for winning the World Series MVP by hitting a preposterous .688 in the series with two home runs, six RBI, and eight walks. Over the last few seasons of his career he served as a mentor to the next generation of stars coming up through the Red Sox system and helped them win the division again in 2016.
While the Red Sox would lose in the 2016 ALDS and Ortiz would retire, he helped set that group on the path that would result in two more division titles and another World Series win in 2018. There’s not much more that can be written about Ortiz that I and others haven’t already expressed. He was, quite simply, the best and most important Red Sox player of both the 2000s and the 2010s.