Notes: Magic number 4 to beat Bobby V

PITTSBURGH -- Quick hits from PNC Park, where the Red Sox will attempt to avoid being swept in a series for the 11th time this season.

• Last season, the Sox were swept just once, a three-game set in Texas Oct. 3-5. That was their fewest multi-game sweeps in a season since 1955, and it was the first time the Sox had played an entire season at home without being swept.

The Sox have been swept at home eight times this season; they have been swept twice on the road: the Rays took three straight in the Trop May 23-25, and the Indians took three straight June 2-4 in Cleveland.

• The Sox are 9-10 in interleague play. A loss Thursday, and the Sox will finish with a losing record against National League teams for the first time since they went 5-13 in 2002. Since then, they have led the majors in interleague winning percentage (139-80, .635).

• The “magic number” remains four: The Sox must win four of their remaining 10 games to finish ahead of the Bobby Sox of 2012, who went 69-93.

Brock Holt, who was examined by concussion specialist Dr. Micky Collins on Thursday, showed improvement, but it’s still uncertain whether he will return to the Sox lineup before the end of the season, manager John Farrell said. If he is unable to do so, Farrell said, the Sox may ask him to play in a couple of games in the Florida Instructional League just to satisfy any lingering concerns that he is fully recovered.

Holt has not played since Sept. 5.

• Cuban outfielder Rusney Castillo, who went 1-for-4 in his major league debut Wednesday, was not in the lineup Thursday, Castillo giving way to Jackie Bradley Jr. in center field. Bradley is 1-for-23 since his recall from Pawtucket 13 days ago. Farrell said the club will spread out Castillo’s days of rest over the last 10 games; he will continue to play after the season is over, with the Arizona Fall League appearing to be the most likely destination.

Red Sox CEO Larry Lucchino, who was in town for pregame ceremonies in which his brother Frank, a Pittsburgh judge threw the ceremonial first pitch with LL catching, was among the first to greet Castillo upon his arrival in the team’s hotel Wednesday.

• Farrell said Steven Wright’s knockabout inning in relief Wednesday will have no effect on whether the club finds a way to give him a start before the end of the season. Farrell said Joe Kelly and Clay Buchholz will each get two more starts, and will fill in around them.

David Ortiz was back in the starting lineup Thursday after sitting out the first two games of the series. Ortiz needs one RBI for his eighth 30-HR, 100-RBI season, the most in club history, one more than Ted Williams.