When training camp opens on July 28, five key players from last season will be missing.

Here are the five players who have moved on:

1. Cornerback Chris Houston was released by the Lions. It was all a little suspicious in the offseason when he couldn’t participate due to a toe injury and then surgery. He has not signed with another team. It’s uncertain which two cornerbacks will start. Darius Slay and Rasheen Mathis are the early favorites.

2. Safety Louis Delmas, who couldn’t find a way to stay on the field due to his bad knee, was released. He signed with the Miami Dolphins. Free agent James Ihedigbo was signed and is expected to start in place of Delmas.

3. Wide receiver Nate Burleson, who is 31, was also cut. Burleson broke his forearm last season in a strange pizza-related incident just after he was coming off a broken leg in 2012. He signed with the Cleveland Browns and will visit Ford Field in the preseason opener for both teams. Golden Tate was signed as a free agent to fill the void.

4. Defensive end Willie Young, who started 15 games in 2013, was an unrestricted free agent who signed with the Chicago Bears. Young stepped in last year after Jason Jones was lost for the season after tearing his patellar tendon in the third game.

5. Quarterback Shaun Hill was a free agent and signed with the St. Louis Rams. Hill was considered one of the top NFL backups. He’s been replaced by Dan Orlovski who is in his second stint with the Lions. He also played for Jim Caldwell at Indianapolis.

(Training camp opens July 28 with eight of the sessions open to the general public starting on Aug. 1.)

(Follow @PaulaPasche on Twitter. Order her book,  “100 Things Lions Fans Should Know & Do Before They Die’’ here. It’s also available at bookstores.)