Who could blame them? After a 2007 season that saw them advance to the National League Championship Series, the D-backs built a big lead in April and seemed like they might run away with the West division title.
It was a quiet month for the D-backs, who took care of their offseason shopping in December when they acquired co-ace Dan Haren from the A's for six Minor Leaguers. That blockbuster trade came on the same day the club dealt closer Jose Valverde to Houston for three players, including Chad Qualls, who would become a key component of their bullpen.
The D-backs reported to Spring Training in Tucson, Ariz., surrounded by the optimism befitting a young team that had won a league-best 90 games the year before.
There was optimism about the recoveries of pitcher Randy Johnson (back) and infielder Chad Tracy (right knee), both of whom had surgeries during 2007, but there was trouble lurking on the injury front.
While it would not become public until the regular season, outfielder Eric Byrnes tweaked his left hamstring the day before he officially reported for Spring Training. The injury would eventually cost Byrnes more than half the season and rob the D-backs of their biggest basestealing threat.
The calm of a relatively uneventful spring was shattered just days before the regular season opener when starter Doug Davis learned he had thyroid cancer.
Davis announced the news on March 29 and said he planned on making his first two starts of the regular season before undergoing surgery to remove the thyroid.
The D-backs opened their 11th season in Cincinnati with a 4-2 win over the Reds thanks to an outstanding performance from Brandon Webb, who seemed to be in midseason form.
It seemed the D-backs could do no wrong in April. They won eight of 10 series, including sweeps over the division-rival Dodgers and Rockies. Webb went 6-0 with a 1.98 ERA while Micah Owings was 4-0 and Haren was 4-1.
The offense was explosive as the D-backs finished the month with 165 runs, second in the NL to the Cubs. Mark Reynolds hit seven homers, while Justin Upton showed his five-tool potential with a .327 batting average to go with five home runs.
The best news of all came off the field as Davis had successful surgery April 10 to remove his thyroid and the prognosis for his future was positive.
Webb ran his consecutive start win streak to nine before finally dropping a decision to the Marlins on May 21 at Dolphin Stadium. The right-hander finished the month with 10 wins, tops in the big leagues
Johnson had a good month as well, going 3-0 with a 3.19 ERA, and Orlando Hudson hit .379 with seven doubles and 10 RBIs.
Overall, though, it was not a good month, as the D-backs dropped a season-high five straight and went 11-17 as their lead in the NL West fell to 3 1/2 over the Dodgers.
The D-backs' slump at the plate extended into June, when the club hit just .224 and went 11-16. Still, Arizona did not lose any ground to the Dodgers, who also went 11-16.
Haren was named the NL's Pitcher of the Month for going 3-0 with a 1.32 ERA. The right-hander should have won three more games, but did not get much offensive support. He struck out 36 and walked eight in 41 innings.
Reynolds was one of the few bright spots at the plate. The third baseman added another six home runs to his total and hit .293.
The month did not start out well for the D-backs, who went into the All-Star break with a 47-48 record and a one-game lead over the Dodgers. But things would get better as the month wore on.
Arizona finished with a 14-11 record, its first winning month since April, thanks to a 9-4 mark after the All-Star break.
The pitchers led the way. After making some mechanical adjustments at the All-Star break, Johnson won four of his five starts and compiled a 1.71 ERA. Meanwhile, Haren continued his run of success with a 1.95 ERA over five starts and Webb was 3-0.
The D-backs looked to be on the brink of putting the Dodgers away towards the end of the month, but their failure to do so would prove costly.
When the Dodgers visited Chase Field at the end of the month, the D-backs held a 3 1/2-game lead. After a 9-3 win in the first game of the series, Arizona was in a commanding lead with Haren and Webb going in the final two games.
However, the Dodgers snapped their eight-game losing streak the following night and wound up beating both Haren and Webb. It was the start of a dramatic turnaround in the West.
After taking two of three from the Cardinals to begin September, the D-backs left for a six-game road trip to Los Angeles and San Francisco with a 1 1/2-game lead.
When they returned after back-to-back sweeps, they trailed the Dodgers by 3 1/2 games, a deficit they would not be able to overcome. The D-backs did pull to within two games with six to play after they won the first game of a four-game set at Busch Stadium, but they wound up losing the next three as the Dodgers clinched the division.
It was a relatively quiet month for the D-backs, who re-signed their entire coaching staff and set about planning their offseason strategy. Rookie Max Scherzer, who was impressive at the big league level in 2008, pitched well in the Arizona Fall League as the team tried to build his innings count for next year.
Johnson waited until the last possible day to file for free agency and offered to take a 50 percent pay cut to re-sign with the D-backs. However, financial limitations prevented the club from taking him up on his offer, and it's possible that his last game in an Arizona uniform was the shutout he tossed on the season's final day.
After making offers to infielders Ramon Vazquez and Mark Loretta, the D-backs filled their hole at second base when they agreed to terms with Felipe Lopez just prior to the end of the Winter Meetings.
Lopez's signing was announced on the same day the club acquired left-hander Scott Schoeneweis from the Mets in exchange for Connor Robertson.
With their two biggest offseason needs filled, the D-backs began to look ahead to 2009, when they hope to recapture the form that made them division champs in 2007.
Steve Gilbert is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.