Going into the 2009 season, if anyone anticipated a National League West team claiming a wild-card berth, it certainly wouldn’t have been the San Francisco Giants or the Colorado Rockies.

Yet, here it is, roughly 90 games into the campaign, and the 49-41 Giants are the wild-card leader. And just a half-game behind them are the 49-42 Rockies.

The contenders one might have expected atop the wild-card standings -- the Brewers, Cubs, Braves and Mets -- are floundering near the .500 mark. Those teams are a good bet to perform better down the stretch, and the two NL West clubs face a decision whether they are buyers or sellers leading up to the July 31 trade deadline.

At the moment, the playoff picture may look just a tad rosier for the Rockies, who are 31-14 since Jim Tracy took over for Clint Hurdle in late May. They have won seven of their last 10 games since the Fourth of July weekend. The surge began with a three-game sweep of the lowly Nats, and continued with a pair of wins in San Diego to open the second half before the Rockies dropped a 3-1 decision to the Padres last night.

A key surprise has been the Colorado rotation, as Ubaldo Jimenez, Jason Marquis and Aaron Cook have been remarkably successful at generating groundballs and victories. Despite pitching half their games in Denver, all three have sub-4.00 ERAs on the season.

The bullpen has been terrific during Colorado’s nine-game surge, posting a 2.73 ERA and .165 OBA -- mostly at home -- en route to four one-run victories and a 5-3 win over the Padres on Friday night. Rockies relievers have allowed just four runs over 21.1 innings (1.69) in the team’s last seven victories.

The offense has been solid, too, delivering 23 doubles and 10 home runs during the Rockies’ 7-3 run. The hottest Rock in this stretch is Todd Helton, who is 13-for-31 (.419) with six doubles and a homer. Troy Tulowitzki has scored nine runs and powered three home runs, and Clint Barmes leads the club with eight RBIs.

The player the Rockies most want to move is Garrett Atkins, who is playing more to be showcased for a trade. The corner infielder is batting .333 (13-for-39) in his last 13 games, bumping his average 20 points to .226.

The team’s recent success may be changing what the Rockies would like to get for Atkins. Perhaps the front office is looking more at the team’s immediate needs. Reportedly the Rockies have set their sights on relievers, as the pen was a key weakness for most of the first half.

Colorado has shown interest in Cincinnati’s Nick Masset, as the Reds have relievers to trade, but Cincinnati Enquirer sportswriter John Fay says the dependable right-hander isn’t going anywhere. There’s also been talk of Seattle acquiring Atkins to replace injured third baseman Adrian Beltre. The Mariners have power arms to spare, but they look less like contenders now than when those rumors circulated at the start of July. The Mets also have inquired about Atkins.

Meanwhile, the Giants had won 10 of 14 games. . . before dropping the final game before the break and losing twice in Pittsburgh to open the second half. The Giants, though, certainly have something the Rockies don’t: a pair of aces in Tim Lincecum and Matt Cain.

Both right-handers are on a roll. In his last five starts, Lincecum is 4-0 with 1.16 ERA and 47 strikeouts in 38.2 innings. Cain has allowed more than a single earned run only once in his last six outings, a stretch in which he is just 2-1 despite a 2.06 ERA and .199 OBA.

Cain has a history of receiving poor run support in San Francisco, and that’s the case again after he was provided all kinds of runs early in the season. He took a line drive off his throwing elbow just prior to the break, but he’s still on course to face the Pirates on Sunday.

Scoring runs has been a season-long problem for the power-challenged Giants. They have stumbled along at 12-10 in their last 22 games, and have scored more than a single run in only three of those 10 losses. Pablo Sandoval, Aaron Rowand and Bengie Molina have carried the offensive load in 2009, and that’s not the same as Ryan Howard, Chase Utley and Raul Ibanez.

Bruce Jenkins of the San Francisco Chronicle says the Giants are keeping an eye on the tradable commodity across the Bay. Oakland is likely to move Matt Holliday, and the Giants would love to keep him out of the hands of other National League wild-card contenders. He hasn’t hit much for the A’s, but a return to the familiar NL West and a chance to play for a contender (or even a pretender) might provide a spark.

With Randy Johnson’s return from the disabled list looming, there’s buzz in the Bay Area about cutting strings with Barry Zito. That may be the long-term solution, but it’s not likely to happen if he gives the Giants a chance to win more often than not.

As bad as the San Francisco offense and Zito can be, that’s been the case of late. He worked 8.1 scoreless innings in a win over Florida on July 7, and pitched 6.1 innings of a 2-0 loss to Pittsburgh Saturday. For now, there are plenty of starting pitchers taking a regular turn who are worse options than the Giants’ free-agent bust.

The two wild-card hopefuls square off in Denver next weekend. That begins a tough stretch for the Rockies, who then embark on a 10-game road trip that includes seven matchups with the Mets and Phillies.

The Giants face a key challenge before they travel to Denver next week. They open a four-game set in Atlanta on Monday, so it’s back-to-back road series with wild-card contenders in the next seven days. Then, the weekend after facing the Rockies, the Giants will host the Phillies for four games.

The trade deadline is less than two weeks away. By then, both teams may have a better idea if they’re playing for this year, or trading away commodities that will make their long-shot playoff bids even more remote.