TAMPA — Bucs coach Lovie Smith volunteered a single name from the defense as standing out in Saturday's preseason loss to the Vikings: rookie LB Kwon Alexander ."He was outstanding," Smith said Sunday of Alexander, who had four tackles in 32 snaps, all during the second quarter. "Made a couple of rookie mistakes, but beyond that, a good start for him."The Bucs moved Alexander, a fourth-round draft pick out of LSU who just turned 21, from strongside linebacker to the middle as training camp started. They signed free-agent Bruce Carter in the spring to take over in the middle after opting not to re-sign Mason Foster , now with the Bears. Asked if Alexander is pushing for a larger role, Smith said he noticed him Saturday."We talk to all our guys. We want them to put us in position where we need to find ways to get players on the football field," Smith said. "It's hard not to take notice with some of the things he's doing. I would definitely (say he's making a case.)" Snap judgment: Last season when C Evan Smith missed a game due to illness, the Bucs plugged in backup G Garrett Gilkey , who had never snapped in a game. The move proved costly, with trouble on the quarterback exchange, most notably on a third-and-goal play that forced the Bucs to settle for a field goal in a one-point loss to the Bengals.With backup C Josh Allen out the past week with an ankle injury and starter Smith done after 16 plays Saturday, the Bucs turned to Gilkey again. Gilkey played only nine snaps but had two fumbled — one high over QB Jameis Winston 's head, another low — and he contributed to a false-start penalty. The Bucs failing to gain a first down in his three series at center."We have to protect the football a lot better than we did," Lovie Smith said of the errant snaps. "High, low. We weren't pleased with that at all. Yes, Josh is out now, but he's been out a while. We need better play, and it starts with that center-quarterback exchange. That hasn't been what we need it to be. I'll even say at practice at times it hasn't been that way. We know that's been an issue, and we'll continue to work to get it better."The Bucs turned to USF grad Jeremiah Warren at center for the remaining 47 offensive plays, with no significant problems. Gilkey started the game at right guard, ahead of rookie Ali Marpet , before moving over in the second quarter. This and that: P Karl Schmitz , signed last week to challenge veteran Michael Koenen , had a higher net average on his four punts (35.3 yards) than Koenen (31.3), with a long of 57. … Starting DEs George Johnson and Jacquies Smith combined for 30 snaps but didn't have a single tackle or sack. … Backup WLB Khaseem Greene tied for the team lead with five tackles, including a forced fumble that went through the end zone for a touchback. … DT Will Gholston had four tackles, including a tackle for loss and a forced fumble. Contact Greg Auman at email@example.com and (813) 310-2690. Follow @gregauman.