According to USA Today’s Bob Nightengale, a Sox acquisition of Adrian Beltre is becoming a real possibility. As per Nightengale’s Twitter account,

“It wouldn’t be surprising if Beltre falls into the Red Sox lap if he doesn’t accept arbitration from the Mariners.”

The move would be predicated by Beltre declining arbitration, which SI’s Jon Heyman reports as a growing likelihood. Beltre, 30, qualified as a Type B free agent this offseason, so he would not cost the Sox a draft pick.

Beltre battled injuries this past season, batting .265/.304/.379 with only 8 home runs in 449 at-bats. Beltre remains an elite fielding third baseman, however, as he posted a 14.3 UZR at the hot corner in 2009.

Should Beltre regain his hitting prowess from previous seasons, he could present a nice upgrade over a declining Mike Lowell. If so, the team would have to find a taker for the incumbent third baseman – a task that has been slow to gain supporters as a large part of Lowell’s contract would have to be shouldered by the accepting team.

An acquisition of Adrian Beltre would be a good indicator that the team is building toward a winner this season. Instead of letting Lowell’s contract expire after the season to prepare for the 2011 free agent class, they would be committing more money to 2010 and beyond – meaning less to spend on next year’s free agent market. The Beltre acquisition could be an important indicator from a front office that has some questioning if the team is in fact building a winner for 2010.