With Washington’s aging defensive line, the Redskins may be forced to find a solution with their fifth overall draft pick.

While safety, cornerback and offensive tackle are also needed, the Redskins are getting old at a key position. A diminished pass rush demands another playmaker up front after last year’s marquee free agent Jason Hatcher had an injury-plagued season and will turn 33 in July.

The Redskins are concentrating on defensive linemen at the NFL combine, which continues through Monday. Most mock drafts have the Redskins taking either Nebraska defensive end Randy Gregory or Missouri defensive end Shane Ray in the first round.

However, Washington might be tempted to trade down if quarterback Marcus Mariota remains available at No. 5 and another team is interested in moving up to get him. If the Redskins were to trade down in the first round, they could take Kentucky defensive end Alvin Dupree.

There isn’t an offensive lineman worth taking at No. 5 overall. Such a high pick should be reserved for left tackles, and Washington already has Trent Williams. Iowa right tackle Brandon Scherff is projected to play guard. Maybe if the Redskins get two first-rounders in a Mariota trade they could be in position to take Scherff, too, but he’s not valuable enough for the fifth selection.

At strong safety, the Redskins could consider Alabama’s Landon Collins if they trade down outside the top 10, but the safer choice would be to wait for Virginia’s Anthony Harris in the second round. At free safety, Mississippi’s Cody Prewitt is the best option, but he’s a late second-rounder, so Washington will probably skip that position in the draft and address the need through free agency.

The Redskins have plenty of needs, but a top defensive lineman would be the most valuable pick. Taking a pass rusher now would give Washington a playmaker opposite of linebacker Ryan Kerrigan, who is essentially the Redskins’ entire pass rush.

Defensive end Stephen Bowen and nose tackle Barry Cofield will both be 31 this season and each started only three games last year because of injuries. The two 2011 free agent signings were solid until last season, but they’re now reserves at best.

Hatcher signed a four-year, $27.5 million deal last year and then underwent knee surgery. He missed the final three games of the season with a separate knee problem and was never the same player who had 11 sacks in 2013 at Dallas.

Nose tackle Chris Baker is the best returning lineman after he emerged last season at age 27, so the Redskins are looking for an end — especially since Jarvis Jenkins has shown little since his promising 2012 rookie season.

Barring a prominent free agent defensive lineman signing next month, general manager Scot McCloughan can look through the 300-plus players at the combine and know that the defensive line is the team’s focus.

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