Second-quarter earnings numbers could be weak for certain gaming stocks, particularly Boyd Gaming ( BYD), according to one research shop that says growth in the Las Vegas casino market slowed during the period.

On the Las Vegas Strip, casinos have been less crowded this year and gaming usage was down over 4% in the second quarter, says Majestic Research, a firm that uses proprietary tracking data to forecast market trends affecting stocks in various industries.

After a couple years of strong revenue growth on the Strip -- often as high as the double digits -- Majestic projects that revenue growth for this past quarter could be in the low single digits. The Vegas "locals" market, located away from the Strip, also is showing weakness, according to the firm.

"We may be seeing some of the concerns that people have had about consumer spending in general," says Majestic casino analyst Matthew Jacob. "In the past, the casino industry has been fairly resilient to anything on the macro level that is tied to the consumer."

High gasoline prices could be one of the major culprits. "A large portion of people come from southern California, and they drive," Jacob says.

The mass-market side of the Strip is most affected by these issues, he says, while the high-end of the market is performing well.

Jacob says that certain MGM Mirage ( MGM) properties may be seeing some strong trends. MGM's properties include the Bellagio, MGM Grand and Mandalay Bay.

Part of the weakness on the Strip this year also stems from tough comparisons to last year's second quarter. That is when the popular Wynn ( WYNN) casino opened and boosted visitation to the Strip.

In the Vegas locals market, Majestic's data shows Red Rock Casino, the new Stations Casino ( STN) property that opened in April, is performing very well, but is hurting same-store sales at nearby casinos located several miles off the Strip, especially Boyd's Suncoast property.

Overall, Majestic expects Boyd to post negative same-store results in the quarter, due to competition from Red Rock and cannibalization from Boyd's own recently opened South Coast casino, which continues to have a disappointing performance, Jacob says.

The opening of Red Rock may also be hurting Station's other properties, and Majestic expects the company's revenue could drop on a same-store basis.

Boyd's stock, in particular, has been under pressure in recent months, falling from a 52-week high of nearly $54.99 in late April to $38.36 Monday.

Three months ago, analysts expected Boyd to report earnings of 63 cents a share for the second quarter. The average estimate has since been taken down to 60 cents. In last year's second quarter, Boyd reported earnings of 56 cents a share. Boyd reports later in July.

Nonetheless, many investors still believe Boyd is an attractive long-term investment , especially since the stock trades at the lowest multiple in the gaming industry.

"It's a wonderful small company that is going through a rough little stretch here," says Shawn Kravetz, president of Esplanade Capital, which owns Boyd.

He acknowledges much of Boyd's customer base is likely being affected by energy costs and other consumer-related issues, but he says the stock is cheap enough and the company has enough great assets that shareholders will be rewarded well over the long haul. Besides its Vegas casinos, Boyd also owns half of the hip Borgata casino in Atlantic City, N.J., with partner MGM, along with several casinos in middle America.