He played in 13 games his rookie year and had 15 tackles. Last year he started nine games at defensive end and had 42 tackles and three quarterback sacks, both team-high marks among defensive linemen.
Arizona changed coaching staffs after the 2003 season, but Johnson never was told by new coach Dennis Green that he was in any jeopardy of not being on the team. Johnson broke his hand early in training camp and played only one play - a 4-yard tackle for a loss - in one exhibition game.
"There was no way I could be mad at myself over being cut because I was never given a chance by the new coaches to make any plays," Johnson said. "I would have thought if they were going to cut me, they would have done it after I hurt my hand. But we had played three exhibition games and everything seemed fine. I went in for one play the fourth game and they took me right out.
"When I came out, the defensive line coach told me to put my helmet down because they had seen enough on film already about what I could do."
Bad news on Sept. 5
Johnson had already finished his weightlifting session Sept. 5 when he was summoned to Green's office.
"I just thought the coach wanted to talk to me," Johnson said. "Then he told me I had not been productive enough to stay on the team. It didn't make much sense to me since my only play was a tackle for a 4-yard loss.
"But everything happens for a reason. The only thing I'm mad about, and maybe learned, is that I should have been in my coach's ear more telling him I wanted to play rather than taking his word that I was fine. But things work out."
The 49ers flew Johnson to San Francisco Monday. After checking on his hand, which is now out of a cast, they offered him a one-year contract that he accepted.
"At this stage, that's what he wanted," said Alvis Johnson, Dennis' father. "This is his third year, so he can become a free agent after this season. If he has a big year, then he can take offers from every team."
The 49ers had re-signed defensive lineman Kevin Ware Wednesday, but later released him before practice after Johnson was added to the roster.
San Francisco could use Johnson Sunday.
"Dennis thinks he might have a chance to start," Alvis Johnson said. "That might be a bit optimistic, but he's just happy to have a chance to play again. Getting cut when he did was hard, but things certainly seem to have worked out fine. We're all very happy to have him with San Francisco."