The Patriots hosted free-agent defensive lineman Luis Castillo on a visit at Gillette Stadium on Saturday, a source confirms.
Castillo, a 2005 first-round draft pick of the Chargers, was listed a "projected target" for the Patriots when free agency began.
Castillo has a background in the 3-4 defense with the Chargers, although it's a different scheme than what the Patriots play. He is coming off a season in which he was limited to one game with a broken left tibia.
Castillo (6-3, 290) previously visited with the Chiefs and his visit highlights the Patriots' offseason plan of rebuilding their defensive line. Outside of Vince Wilfork (86.6 percent playtime in 2011), Kyle Love and Brandon Deaderick, the Patriots have some question marks up front.
The team has already added Jonathan Fanene (Bengals). At this time, nothing appears imminent with Castillo, but he's a player to keep on the radar.
Ian Rapoport of the Boston Herald first reported the visit.