ST. LOUIS -- , his left knee wrapped and braced, exited the victorious locker room on crutches, bound for the bus that would set him on course to a diagnosis that wasn't good, but wasn't dreadful either: a significant MCL sprain that would sideline him for four-to-six weeks. didn't seem down or in too much pain as he left the Edward Jones Dome after over the , a victory muted by Roethlisberger's injury. players and coaches didn't have time to feel bad for themselves either, shifting quickly to "What's next?" mode, a posture they've been in many times before when Roethlisberger has been hurt or suspended.You could immediately sense, with a later this week, that players realized foes would see them as vulnerable. The schedule is unforgiving, as well. Despite the ' struggles, it's still Baltimore-Pittsburgh. And immediately following that rivalry bout, contests , , and await.The expected "next man up" rally cry was preached in the locker room, and it's sincerely believed in the moment. But there also were some harsh realities to face, just like there were in Dallas, New Orleans and Chicago when those teams lost their respective starting quarterbacks to injury earlier this season.Quarterback , added in late August when veteran backup sustained a season-ending injury, has to conjure up the mojo he seemingly lost over the past few seasons in New York and Philadelphia to guide maybe the best team for which he's ever played.The improving defense has to continue the course it's on, and the running game, which just got a huge boost with Sunday's season debut of All-Pro tailback , has to reclaim Brent Honeywell Jersey an offensive philosophy that has shifted to a pa s-first approach."We're all profe sionals here," Vick said. Bell, after serving a two-game suspension, returned with 132 yards from scrimmage and a touchdown against the . Not knowing the severity of Roethlisberger's injury immediately after the game, he said he was ready to step up. He will be called upon because the well-oiled pa sing game Roethlisberger was guiding won't be the same.Before improving to 2-1 against the , offensive coordinator Todd Haley expre sed how excited he was about the progre s Roethlisberger had made in his fourth season in this system."A trust has been built," Haley said at the time. "He's a believer in the offense and it shows. He knows he's playing the best football of his career. As a coach, you won't have any i sue -- ever. Guys want to be coached and be their best. Actually starting at the end of 2013, we started rolling and it built into last year. As the season went along, it was awesome to see unfold. Then, he had a great offseason."I am so happy, despite mi sing key pieces (Bell for two games, , ), that he has had the succe s he has. That game last week ( over the ) was near perfect. Mentally, his decisions, our ability to run the no-huddle and to have him handle it at the level he did was near perfect."So were things before Roethlisberger went down in the third quarter in St. Louis. He was 20-of-24, using a short, quick, precise pa sing attack to best alleviate the pre sure the ' front seven was bringing. What Roethlisberger has going with wide receiver also is nothing short of a synchronized beauty.They'd connected on 11 pa ses for 108 yards against the before went down. It looked so easy, just as it has been all season between the two. They've connected 29 times for 426 yards and two touchdowns in three games.That likely won't continue with Vick. We saw that Sunday when he had to step in for Roethlisberger and did just enough, with the help of a strong defensive effort, to defeat the ."This is the fourth offense I've had to learn," Vick said.As Haley said, it's taken Roethlisberger years to click in this pa s-first system. As for Brown, Haley said, "Two or three years ago, we tried to move him around and he couldn't handle it. Now he's grown so much and is so much more detailed that we can move him around. That's critical."So, how will the operate under Vick in the short and long terms? Haley said that Vick is familiar with the philosophy of the offense, so there won't be any seismic shifts with what they've done. However, there will be a greater emphasis on the running game. This is a pa sing attack that takes time to learn and Vick simply hasn't been with the team long enough. Plus, once the regular season started, he received minimal reps behind Roethlisberger. Still, Vick's experienced enough to handle what will be asked of him and has the type of personality that players gravitate toward. Teammates won't doubt his ability.Vick also is one of the most competitive people on the planet, which is why he tends to always try to make something happen on each play, even though sometimes that is a detriment. The focus now is simply to be sound and careful, with the hoping to use the run game and defense to grind out victories."I was brought here for a reason," Vick said. "I have to hold it down until No. 7 gets back."Follow Steve Wyche on Twitter . Charlie Hough Jersey