Japanese ace Masahiro Tanaka, who last month signed the fifth-largest contract for a pitcher in major league history, has the potential to be a "No. 3 starter," New York Yankees general manager Brian Cashman said Friday.

"We view him to be a really solid, consistent No. 3 starter," Cashman said on "The Herd with Colin Cowherd" on ESPN Radio. "If we get more than that, all the better. He's got a great deal of ability.

"There is definitely some unknown because of the transition. We scouted him extensively. Certainly, we look forward to adding him into the mix with the rest of our rotation. That's what we look at him as: A solid, potential No. 3 starter in the big leagues."

Cashman is likely trying to tamp down expectations for the 25-year-old Tanaka, who signed a seven-year, $155 million contract with the Yankees -- the largest contract ever given to an international player. Tanaka can opt out of the deal after four years.

The Yankees will officially introduce him at 1 p.m. ET Tuesday at Yankee Stadium.

The Yankees have not had much success signing Japanese pitchers, with their previous largest expenditures being for Hideki Irabu and Kei Igawa.

In 2013, Tanaka went 24-0 with a 1.27 ERA in Japan. The Yankees had scouted him for years and outbid several other teams for his services. Even with those numbers, the contract and a splitter that is said to be among the best in the world, Cashman said nobody should expect an ace -- especially right out of the gate.

"That's asking too much," Cashman said. "Clearly, he is going to have to transition from Japan to the States. Obviously, by the fierce negotiating competition for him, the scouting reports from all clubs involved speak for themselves."

Cashman expects Tanaka to have "some growing pains" as he adjusts, especially when it comes to pitching every five days as opposed to every seven days in Japan. He also cited differences in the baseball and the strike zone, as well as stronger opposing lineups, as other potential hurdles.

"Those are things he is going to have to work through and adjust," Cashman said. "We look forward that he is a Yankee and we will be in position, with our experience in the past, to maximize his potential as he goes through that.

"No, he is not someone who is going to, in the front end of this thing, pitch in the front of the rotation."