Miami Dolphins wide receiver Mark Duper has a hairline fracture of a bone in his left leg and will be lost to the team for six weeks, Coach Don Shula said yesterday.

Starting linebacker Charles Bowser suffered a severely sprained ankle Sunday against Indianapolis and will be out two to four weeks.

Duper said he injured his leg in practice Friday, but he practiced Saturday and told coaches after practice his knee was sore. Duper played a few plays Sunday against the Colts in Miami's 30-13 win and then left the game. Duper will be placed on injured reserve and will have to wear a splint for four weeks.

*St. Louis Cardinals: Left cornerback Lionel Washington suffered a fractured right ankle with 37 seconds left after colliding with Cincinnati receiver Cris Collinsworth Sunday. Outside linebacker Thomas Howard twisted his right knee in the second quarter trying to bring down running back James Brooks.

Washington, placed on the injured reserve, will be in a cast for six weeks and then take a minimum of two weeks for rehabilitation.

Howard will undergo an arthroscopic examination today. Even if it proves negative, he will be out four to five weeks.

*Dallas Cowboys: Tests showed that quarterback Danny White suffered a sprained right thumb and wrist in the team's 26-21 loss to the Detroit Lions. X-rays ruled out any broken bones in the injury White suffered in the first quarter of Sunday's game. White played three quarters before leaving the game.

*Tampa Bay Buccaneers: Signed veteran running back Ron Springs, who was released earlier this month after six seasons with the Dallas Cowboys, and waived running back Melvin Carver.

*Atlanta Falcons: Starting safety Kenny Johnson will be out at least 10 weeks with a broken shoulder blade. Two other defensive backs were placed on injured reserve following the Falcons' 35-16 loss to the San Francisco 49ers Sunday. Starting cornerback James Britt suffered fractures to two bones in his right leg in the game and will be lost for the season. Rookie cornerback Tiger Greene will miss at least five weeks after suffering cartilage damage to his right knee.

Defensive backs Reggie Pleasant and Wendell Cason, both cut in preseason, will be activated today, Coach Dan Henning said.

*New Orleans Saints: Linebacker Jim Kovach, the team's leading tackler the past three seasons, underwent knee surgery and will sidelined for as long as 10 weeks.

*San Francisco 49ers: Keena Turner, the Pro Bowl linebacker who was forced out of Sunday's game because of a sprained ankle, is considered doubtful for next Sunday's game in Los Angeles against the Raiders.