In this Hobson piece -- which appears to be the same running piece -- says that Johnson is running drills, but has Charles Collins, Johnson's "closest mentor and junior college position coach." Even though ESPN's Bob Holtzman (who appears to be here because of Chad), who was told by Chad himself that he's "hurt", Chad put on his jersey and "jogged to the practice".
Johnson was on time for an 8 a.m. team meeting and on the field at 9:57 -- 13 minutes after the scheduled time.
UPDATE: Chad not practicing. No explanation given. Per Hobson (in the long-running minicamp piece):
Once on the field, Johnson watched his wide receiver teammates run a receiving drill, but he stood on the side and did not participate. It did not appear that he interacted with any of his teammates during the drill.
Later in practice as the receivers ran routes Johnson pretty much watched on one knee or stood off by himself. He occasionally chatted with fellow Pro Bowl wide receiver T.J. Houshmandzadeh, had a few words for second-round pick Jerome Simpson and came over to say hello to cornerback Leon Hall. He also greeted backup quarterback Jeff Rowe at one point.
During the special teams session Johnson chatted on the sideline with cornerback Johnathan Joseph and had some interplay with tight ends coach Jon Hayes.
The Bengals had no explanation why Johnson was not practicing.