Croyle, coming off knee surgery, finished with 16 completions in 24 attempts for 210 yards with one interception and one touchdown.
Darby, who had surgery to repair a sports hernia last winter, had 17 carries for 90 yards and caught two passes for 17 yards.
Castille, who had surgery to repair two torn knee ligaments, had five carries for seven yards, but had two touchdown runs. He also had two pass receptions for 13 yards.
Alabama returns to Bryant-Denny Stadium next Saturday, hosting Southern Miss at 6:45 p.m. CDT in a game that will be telecast by ESPN2. It will be the first game for the Golden Eagles, whose season-opener was to have been against Tulane in Hattiesburg this week. That game was cancelled due to Hurricane Katrina.
Alabama's defense was expected to be strong this year. Still, it was something of a surprise when the first score of the year for the Crimson Tide was defensive end Mark Anderson catching MTSU quarterback Clint Marks in the end zone for a safety. That was the only score of the first quarter.
Tim Castille, who had been questionable for this season after undergoing knee surgery in the middle of the 2004 season, scored the first touchdown of the season for Bama, going in from a yard out to cap a 10-play, 51-yard drive that consumed 4:30. A key play in the drive was Croyle connecting with Ezekial Knight on a third down play. Knight also had a 15-yard reception to get the drive started. Ryan Saxby's extra point made it 9-0.
The Blue Raiders didn't roll over. MTSU came back with a three-minute scoring drive, going 80 yards in nine plays with the touchdown a 14-yard pass from Marks to fullback Nick McAbee. Marks made an excellent fake on McAbee was open behind the Tide defense in the end zone to cut the Bama lead to 9-7, which was the halftime score.
Marks finished with 12 of 18 for 117 yards.
Alabama looked to be off and running on MTSU's first punt of the second half when Tyrone Prothro returned it 54 yards to the Blue Raiders' 14-yard line. However, a clipping call put Bama back at its own 32. Darby had five straight runs for 55 yards to set the Tide up at MTSU's 13 yard line. From there Croyle hit Tyrone Prothro on a 13-yard scoring pass. The drive took six plays and covered 68 yards in 2:38. That made it 16-7.
Bama got a quick break when the ensuing kickoff was fumbled and recovered by freshman Chris Keys at the MTSU 19. But Darby lost four yards on first down and failed to gain on second, and a Croyle pass was incomplete, forcing a 41-yard field goal. Saxby made it, but Bama had only 10 men on the field and the 46-yard re-try was no good.
Alabama came back with an impressive drive, 59 yards in six plays. With Croyle hitting Matt Caddell on a 24-yard pass and Darby running tough inside, the Tide went to a first down inside the one-yard line. Tim Castille took it in from there for a 23-7 lead with just under three minutes to play in the third quarter.
It may have been a bit of a surprise that Croyle returned to action in the fourth quarter. The senior quarterback, who had been injured in mop-up duty last year, drove the Tide deep into MTSU territory where Saxby was good on a 32-yard field goal to give Bama a 26-7 lead.
With 10:13 to play, Alabama's second offense–including back-up quarterback freshman John Parker Wilson, took over.
Alabama dominated statistically even more than on the scoreboard. The Tide had 20 first downs to nine for MTSU. Bama rushed 37 times for 133 yards, while the Blue Raiders managed only 34 yards on 25 runs. The Tide had 212 yards passing, Middle Tennessee 123.
Alabama had 62 plays for 345 yards, an average of 5.6 yards per play. MTSU had 45 plays for 157 yards, an average of 3.5 yards per play. Bama dominated in time of possession, 33:06 to 26:54.
Keith Brown was the top Tide receiver with five catches for 84 yards. Matt Caddell had three for 50, Zeke Knight two for 21.
A pre-game announcement from the athletics department was that four players were suspended for the game. Although they were dressed and on the sidelines, placekicker Jamie Christensen, quarterback Marc Guillon, running back Aaron Johns, and strong safety Marcus Carter were disciplined for an undisclosed violation of team rules. >p> Alabama had a new kickoff return alignment with Tyrone Prothro lone deep man. He fumbled opening kickoff, but it was recovered by Ezekial Knight. Prothro was also the punt return man.
Freddie Roach did not start at middle linebacker. He appeared to be injured on Bama's first punt. The starting linebackers had DeMeco Ryans in Roach's spot and Terrence Jones starting for Ryans at strongside linebacker. Roach was in street clothes in the second half with his arm in a sling. Offensive guard Mark Sanders appeared to suffer a leg injury in the third quarter.
Junior safety Jeffrey Dukes was the nickel back when Alabama went to a five-man defensive secondary scheme.
Tim Castille's first appearance of the year was at halfback on a third-and-one play when the Tide went to its jumbo package to make a first down.
In the first game with a replay official in the press box (new in the Southeastern Conference this year), the replay official was Ben Oldham and the communicator working with him was Jimmy Harper, the most legendary official in SEC history.
The game ball was delivered by Jim Bunch, a 1979 All-America offensive tackle.
In temporarily-reduced Bryant-Denny Stadium, the Crimson Tide had a sellout of 81,018. The stadium is short about 2,000 seats due to construction that will boost capacity to some 92,000 by the start of the 2006 season.