U.S. stock futures struggled for direction Friday morning as investors awaited an update on inflation, which is expected to hover near a 40-year high amid elevated prices for gas, food and a variety of other goods and services.

Contracts on the S&P 500 and Dow were each off by about 0.2% in pre-market trading. Nasdaq futures traded flat to slightly higher. Treasury yields rose along the short-end of the curve, while the benchmark 10-year yield steadied around 3.03%. U.S. crude oil prices rose 0.7% to trade above $122 per barrel, holding near the highest level since March.

For market participants, the Bureau of Labor Statistics' 8:30 a.m. release of the Consumer Price Index (CPI) will be a key print, offering a fresh look at the extent to which price increases have persisted across the U.S. economy. Consensus economists are looking to see inflation rose 8.3% year-on-year in May, according to Bloomberg, matching April's clip and coming in just a hair below March's more than 40-year high rate of 8.5%.

CPI is also likely to accelerate to a 0.7% month-over-month clip in May from April's 0.3% rise, tracking a surge in gas prices heading into the summer travel season. Core inflation, which excludes volatile food and energy prices, is expected to edge down only modestly to a 5.9% annual gain from April's 6.2%.

Inflation has remained a dominant issue for investors, policymakers and the American public this year. Higher prices have threatened to weigh on consumer spending — the key driver of U.S. economic activity — as goods and services become increasingly unaffordable. And inflation has already shown signs of triggering a rotation from spending on some discretionary goods to other purchase areas.

And for investors, inflation has also become a key determinant in the path forward for the Federal Reserve's monetary policies. As the Fed aims to help bring down fast-rising prices, the central bank is widely expected to raise interest rates by another half-point at next week's policy-setting meeting, further increasing the cost of borrowing and doing business for companies.