SEATTLE — Finally, the Seahawks found a reason to keep a pick.

After opening Friday’s session of the NFL draft by again trading down to acquire an extra pick later, the Seahawks decided to write down a name and send it in.

And the name, general manager John Schneider said, was the same one that Seattle was ready to submit before trading twice earlier in the draft — Colorado receiver Paul Richardson.

“We had to have a name ready in New York (where the draft is officially held) and it was Paul’s name,’’ Schneider said. “So we were really excited that we were able to go back and (get him).’’

Not, though, before a few anxious moments.

The Seahawks worried that the Eagles — who took two receivers on the day — would draft Richardson when they moved into the 42nd spot.

That, according to Schneider, compelled director of college scouting Scott Fitterer to tell Schneider “let’s not trade anymore.’’

Seattle moved down to 45 in a trade with Detroit in which the Seahawks also gave up the 146th pick of the fifth round to acquire the 111th pick in round four and the 227th pick in round seven.

That gives Seattle eight picks for the draft — it entered the event with six, which would have been the team’s fewest since 2006 — with six coming in rounds four through seven, to be held on Saturday.

Seattle then used its own pick at the end of the second round, No. 64 overall, to select offensive lineman Justin Britt of Missouri.

Britt will be used initially at right tackle, where he will compete with second-year player Michael Bowie to replace Breno Giacomini, who signed with the Jets as an unrestricted free agent.

Both players were picked a little ahead of where most pundits had them slotted.

Some draftniks had concerns over Richardson’s size — he’s 6-foot and officially listed at 175 pounds, though he said he played in college as low as “158 to 161.’’ Richardson, though, said he weighs 183 now and the team said it was not concerned about his size.

Richardson also played for three coaches in four years at Colorado.

Richardson caught 156 passes in 33 games, including 83 last year as a junior — he declared for the draft with a year of eligibility remaining.

Seattle wasn’t concerned about the events that led to Richardson ending up at Colorado in 2010. He was a highly-touted receiver out of Juniperro Serra High in the Los Angeles area, signing with UCLA. But Richardson was arrested for felony theft in July, 2010, along with Bruins teammates Shaquille Richardson (a cousin) and Josh Shirley. All were kicked off the team, with Shirley ending up at Washington and Shaquille Richardson at Arizona.

The three later pleaded guilty to a misdemeanor.

Matt Berry, Seattle’s Southwest Area Scout who spent three days with Richardson at the NFL Combine in February, called it “an immature incident that was blown out of proportion.’’

Richardson met with a Seattle team psychologist, which Richardson called critical, saying “he felt that I would be able to fit in’’ with the Seahawks.

Richardson could be a candidate to return punts. But the Seahawks mostly envision Richardson adding a speedy and quick receiver who can spread the field and has big-play ability.

Britt was even more off-the-radar, projected by some pundits as being a sixth- or seventh-round pick. Britt himself said he thought he might go anywhere from the seventh round to going undrafted.

Offensive line coach Tom Cable, though, said he was impressed by Britt’s athleticism — he was a state champion heavyweight wrestler as a senior in high school — and maturity.

Britt started all 14 games at left tackle last year for Missouri.