The source would be surprised, however, if Bell isn't back with the Steelers shortly after that, citing his love for football.
Bell can always rearrange his plans, but currently he's slated to remain training on his own for at least the next few days.
The two sides tried to hash out a long-term deal before the July 17 deadline expired for players with franchise tags to sign extensions. Instead, Bell skipped training camp and hasn't signed his $12.1 million franchise tender. He has been in South Florida for most of August.
The Steelers play their third preseason game Saturday against the Indianapolis Colts, with the first-team offense set to play well into the first half. The third preseason game is traditionally where starters receive their most preseason game action.
Filling in for Bell Sunday, third-round pick James Conner had 98 yards on 20 carries against Atlanta.
One Steelers player privately told ESPN that he expects Bell to return shortly before Labor Day.
One potential good sign for Pittsburgh is that Bell has been in communication with his offensive line via text messages.