"All teams have injuries, but when you lose four of your starting pitchers by the All-Star break, three by the first or second week in May -- it's going to have an impact on any club, in my opinion, regardless of how good their farm system is," Steinbrenner said.
"That's certainly been part of it. But we put a lot of money into the offense as well, and they have been, as a whole, inconsistent. It's been a problem. And it needs to change, needless to say."
The Yankees entered play on Wednesday ranked 11th in the American League in runs scored (471) and OPS (.696), and ninth in home runs (107). They had scored in just three of their past 29 innings, and they've scored one run or fewer in 22 games this year.
Steinbrenner, who authorized the July acquisitions of Stephen Drew, Chase Headley and Martin Prado in an attempt to upgrade the lineup, said that he wants to see the production improve over the season's final 44 games.
"They have to. They know that," Steinbrenner said. "They're professionals and the talent is there. But they've got to step it up and they know that. ... Look, my job is to be an optimist, and I am confident."
Steinbrenner added that he has not made any decisions about general manager Brian Cashman's future. Cashman has held his current position since February 1998, and his current three-year contract expires after 2014.
"We're so busy right now trying to figure out who's going to be playing in any given game," Steinbrenner said. "We'll be talking about that soon enough, but we've got enough things to worry about during the season. That's where our focus needs to be.
"Let me get to October -- hopefully the end of October, the beginning of November -- and we'll go from there. That's what he's planning for and that's what we're planning for."
Steinbrenner also said that he has had no recent conversations with suspended slugger Alex Rodriguez, but the Yankees are expecting A-Rod to return next season. Rodriguez will have three years and $61 million remaining under contract when his suspension expires.