Photo courtesy of Bolton Wanderers

Philadelphia Union manager John Hackworth confirmed the team has considered acquiring former Bolton captain Zat Knight.

Hackworth spoke with the 6-6, 33-year-old center back’s agent a few weeks ago, Hackworth said Tuesday during a conference call with media. The Union could still sign him, Hackworth said, but the Union manager indicated the team is considering other center backs in other countries as well.

Knight is in the last year of his contract with Bolton, which plays in England’s second division after being relegated in 2012. He has two caps for England and spent 12 seasons in the English Premier League with Bolton, Aston Villa and Fulham.

Currently, the Union have one center back slot locked down by Amobi Okugo. Philadelphia acquired 23-year-old center back Ethan White and drafted rookies Richie Marquez and Kevin Cope last month.

Hackworth said he has seen some “pleasant surprises” from the trio of new center backs, each of whom is competing for a starting spot.

However, Hackworth has been open about the team’s desire to potentially bolster the position with a veteran acquisition since starter Jeff Parke was traded to D.C. United as part of the deal that gave the Union the right to sign midfielder Maurice Edu.