As a senior at Vanderbilt University, Rams rookie running back Zac Stacy set career marks for rushing yards (3,143) and touchdowns (30). All 30 of his scores came on the ground. Last weekend, in the Rams’ 30-15 road loss to the Carolina Panthers, Stacy picked up his first professional touchdown when he hauled in a 4-yard pass from Sam Bradford with just under 5½ minutes to play in the third quarter. “A little bit of a surprise I guess, but I’ve been working on my pass-catching,’’ he said. “It was kind of hard, coming in a loss, but it’s still a good milestone. That touchdown in that game didn’t mean a whole lot, but hopefully there will be more in my career that I’ll be able to celebrate.’’ A key figure in the Rams’ revitalized run game in recent weeks, Stacy rushed 17 times for 53 yards and caught four passes for 34 yards and a touchdown against the Panthers. And he figures to be busy again when the Rams (3-4) host the Seattle Seahawks (6-1) for a key NFC West showdown on Monday Night Football from the Edward Jones Dome. But even with Bradford out with a season-ending knee injury, Stacy stressed that it’s been business as usual this week at Rams Park. “Losing Sam obviously hurts, but (back-up quarterback Kellen Clemens) is going to get the job done,’’ said Stacy, who has rushed for 214 yards while averaging 4.3 per carry. “It’s not just the running game that has to step up, it’s everybody on the team. As a team, we just have to stick together, to continue working to keep the process going.’’ Defensively, the Seahawks are ranked second overall — they’re sixth against the run and second against the pass. But that seems to be par for the course for the Rams, who are coming off games against No. 1 Houston and No. 3 Carolina. “It’s what you deal with in this league,’’ Rams offensive coordinator Brian Schottenheimer said. “Even the ones that are down there at 31, 32, they’re pretty good, too. Obviously, we know these guys; they are clearly one of the best defenses in the league. Excellent front seven. They went out and spent a lot of money on extra pass rushers ... and their secondary is probably the best in football.’’ Stacy echoed that: “We all know about Seattle. Just an all-around outstanding unit. We still prepare the same way and we’re still going to play to our strengths. It all comes down to execution.’’ Off to their best start in franchise history, the Seahawks are not about to let down now. At least not if head coach Pete Carroll has anything to say about it.