The Eagles promoted safety Keelan Johnson from the practice squad on Tuesday.

Johnson said he was so confident about his future in Philadelphia that he declined an appealing offer elsewhere because he felt his time would come with the Eagles.

"I spent all this time here, I figured it was going to happen sooner or later," said Johnson, who played for Arizona State.

The Cardinals were interested in adding Johnson after safety Tyrann Mathieu hurt his knee on Dec. 8. Johnson would have been guaranteed a roster spot for four weeks and credited for an accrued season.

But Johnson had been with the Eagles for more than three months, learned the defense, and was confident that he'd have a better chance of excelling in Philadelphia. He didn't know when it was going to happen, but injuries to Colt Anderson and Kurt Coleman in Sunday's loss to Minnesota prompted the Eagles to make a move.

"If you have to bring a guy up, we'd rather bring a guy up from the practice squad because he's been here," coach Chip Kelly said. "He understands our system. It's not trying to get a guy on a Tuesday, trying to tell them what our calls are, what the fits are. . . . He's a big kid, physical kid."

Johnson's primary responsibility will likely be on special teams, where he is expected to fill Anderson's spot. Anderson's knee injury is considered more serious than Coleman's hamstring injury.

With uncertainty about the Eagles' safety situation, Johnson will have a chance to impress the team's decision makers.

"My first game is going to be as an Eagle, and it's home, it's a whole different feeling," Johnson said. "Everything's on the line for this game, so I've got to be even more mentally sharp."

Extra points

Cornerback Brandon Boykin (concussion) continued to miss practice because of the league-mandated concussion protocol, but he told WIP-FM (94.1) that he should be able to play barring a setback. Coleman and Anderson were the other two players to miss practice. Safety Earl Wolff (knee) and linebacker Najee Goode (hamstring) were full participants after missing extended time. . . . The Eagles signed Emmanuel Acho to the practice squad after releasing him from the active roster on Tuesday to make room for Johnson.