ASHBURN -- Things change quickly in the National Football League.

 Sometimes "NFL" really does stand for "Not For Long."

Yesterday the Washington Redskins felt downcast after their first preseason practice. They lost starting left defensive end Phillip Daniels for the season to a knee injury.

But the Redskins felt excited after their second practice of the day because they had acquired defensive end Jason Taylor, one of the premier pass rushers in the league, to replace Daniels.

The Redskins gave the Miami Dolphins a second-round draft choice in 2009 and a sixth-round pick in 2010 in exchange for a player who has 117 sacks in 11 seasons.

"We had to act after losing a starting defensive end," said Vinny Cerrato, the Redskins' executive vice president for football operations. "We're fortunate there's a guy that caliber on the market when somebody got hurt.

"He's a six-time Pro Bowler and was the defensive MVP of the league in '06. The timing was right."

Taylor's relationship with the Dolphins had become contentious. The team was not happy that he had participated in the television show "Dancing with the Stars" instead of working out with the team in the offseason.

And Taylor wanted to be traded to a team with the potential to make the playoffs instead of staying while the Dolphins rebuild from the rubble of a 1-15 2007 season.

The Redskins were a wild-card playoff team last season and, until Daniels' injury, had every starter returning from 2007.

While Taylor, 33, is not an exact replacement for Daniels, a strong run-stopping defensive end, Taylor will line up in Daniels' spot on the left side.

Taylor has spent most of his career on the right side, where teams usually place their best pass rusher. But the Dolphins have moved him around, and he also has played as a stand-up defensive end at times.

"One of the more impressive things he's done, he's played about 90 percent [of the time] every year," Cerrato said. "He's got statistics to back up everything he's done."

Taylor ranks 14th all-time in the NFL in sacks and has the most of any active player. His best sack season was 2002 when he had 18½. He also has returned three interceptions for touchdowns.

Taylor had indicated he would play just one more season, but the Redskins were not deterred by that.

"I'm 100 percent confident he'll play much longer than that," Cerrato said. "He's got two years left on this deal. It's totally new environment for him. He's excited for a new start."

Taylor started NFL career as a third-round selection of the Dolphins in the 1997 draft, out of the University of Akron. He has started 169 of the 172 games in which he has played. He has not missed a game since the 1999 season.

The Redskins had ample room for Taylor in their salary structure. Cerrato said the team has more than $8 million in salary-cap space before the acquisition of Taylor.

Yesterday was quite a day for Jim Zorn, the Redskins' head coach. He began his first practice as a head coach at any level by watching Daniels being taken off the field on a golf cart.

An MRI revealed Daniels had a torn anterior cruciate ligament. After surgery, the recovery time usually is six months.

In the afternoon, Zorn watched as Alex Buzbee, a first-year backup defensive end, was lost for the season with a ruptured Achilles tendon.

"They were both non-contact injuries and hard to predict," Zorn said. "There's just nothing we can discuss to say, 'What if? What if we had done this or that?'"

But when Zorn left the team's practice facility last night, he was the coach of the team with the potential to have one of the most potent pass rushes in the NFC.

. . .

IN ADDITION: Starting cornerback Fred Smoot suffered a sprained ankle in the afternoon practice but is not expected to miss more than a few days.