Mike Tomlin doesn't know when Le'Veon Bell is going to show up for work.Maybe it'll be in time for the Pittsburgh Steelers All-Pro running back to be ready for Sunday's season opener at Cleveland.Or maybe Bell will skip a week to send one last message about his frustration over not being able to sign a long-term deal during the offseason.Or maybe Bell will wait until early November to sign his one-year franchise tender , a move that would cost him millions in lost salary up front, a windfall Bell hopes to recoup when he hits free agency next spring.Tomlin insists he has too much going on getting ready to chase a third straight AFC North title to keep checking Bell's locker for evidence of his arrival."When he gets here, that's when we'll start quantifying Le'Veon Bell-related things," Tomlin said Tuesday.Though Tomlin has been in contact with Bell during Bell's lengthy sabbatical -- the three-time Pro Bowler's last appearance with the team was during a playoff loss to Jacksonville in January -- Tomlin has no idea what to expect whenever Bell signs the contract that will make him both the highest-paid running back in the league and start the countdown to his departure in 2019.So Tomlin declined to get into specifics about how long it might take for Bell to get ready to play after not practicing for eight months. Could be a week, as it was last year. Could be longer."Right now, (I'm) singularly focused on the guys focused that have been here," Tomlin said.Second-year running back James Conner chief among them. The former Pitt star made significant strides during training camp. Following an uneven rookie season in which he dealt with various health concerns -- including a knee injury in December that landed him on injured reserve -- Conner's rise over the spring and summer left his teammates confident and his head coach impressed.Asked if he's more comfortable with the depth behind Bell than he was heading into the 2017 opener, Tomlin said yes. When asked why, Tomlin simply replied "James.""The status and condition and the approach of James," Tomlin said. "We had a rookie that missed a lot of time due to soft tissue injuries and lack of general readiness to a guy that's done the things that we've outlined."The Steelers drafted Conner in the third round in 2017, capping a remarkable 18 months in which he recovered from a cancer diagnosis in November 2015 to become the ACC's all-time leading touchdown scorer at Pitt.Conner tweaked his hamstring on the first day of rookie minicamp shortly after being selected and only showed flashes of the player who ran for 3,733 yards and found the end zone 56 times for the Panthers.Conner ran 23 times for 144 yards while occasionally spelling Bell last season. Now he finds himself atop the depth chart until Bell arrives.Conner looked the part of a starter during the preseason, running for a team-high 100 yards, including a bruising 26-yard touchdown run against Green Bay's starting defense. Conner has also drawn raves for his improvement as a receiver out of the backfield -- a weakness last summer -- and his work in pass protection."If we start off with James, I think we'll be fine either way," guard Ramon Foster said. "He's a guy that's made strides. He's made us confident in him. So he gets the start, we roll with him. No disrespect to (Bell), we've got to move. This is a moving train."NOTES: Tomlin said he believes the team is relatively healthy heading into the opener and did not rule anyone out for Cleveland. WR Antonio Brown (groin) did not play at all during the preseason. TE Vance McDonald (foot) has been out since the first week of training camp while CB Mike Hilton and rookie WR James Washington (oblique) were slowed in late August. ... Tomlin said he's fine with the depth at outside linebacker, but did not rule out whether the team would look to add at the position.