The Redskins yesterday obtained 6-foot-2, 230-pound fullback Don Testerman from the Seattle Seahawks in exchange for a fifth-round draft choice in the 1980 draft.

The two teams also will exchange seventh-round choices in the 1979 draft, according to Genral Manager Bobby Beathard.

Beathard originally drafted Testerman in the 10th round of the 1976 draft for Miami. The Clemson University player was traded to Philadelphia during the preseason and then was picked up on waivers by Seattle before the regular season opened.

He started a number of games for Seattle, but his playing time dropped appreciably last season and he asked to be traded. In three seasons at Seattle, Testerman gained 860 yards in 229 carriers and also caught 73 passes.

"he will help us because he's an outstanding blocker and receiver," Beathard said. "We could even use him in a double-tight-end situation. He has good speed and fine hands."

Testerman becomes only the second true fullback on the team, behind starter John Riggins.Riggins, 29, has two years remaining on his contract and he said he seriously will consider retiring when that pact runs out.

Beathard said that three other teams also were involved in the bidding for Testerman the past two days. The general manager said that Tenterman was the top back in Miami's 1976 camp, "but it was a numbers thing . . . We just had veterans who were good, also, and Don (Shula) didn't feel we could keep him."