Source: Pats work out DT Spencer Johnson

The Patriots worked out veteran defensive tackle Spencer Johnson on Thursday, according to a league source.

Johnson, 31, spent the past five seasons as a member of the Buffalo Bills after four seasons with the Minnesota Vikings, whom he signed with as an undrafted free agent in 2004.

The 6-foot-3, 304 pound Johnson has career totals of 303 tackles and 14 sacks during his nine pro seasons. His best year came in 2010, during which he started six of 14 games played and finished with 55 tackles and a pair of sacks.

He became a starter for the Vikings during his rookie season, finishing with 40 tackles in just nine games played. After signing with the Bills as a free agent in 2008, Johnson started 20 of 76 games played.

The Patriots have had a flurry of defensive tackle transactions this offseason, signing veteran Tommy Kelly and CFL product Armond Armstead, while releasing Kyle Love and Brandon Deaderick, who shared starting duties alongside Vince Wilfork in 2012.