"I'm not sure if Robertson is capable yet. He's never done that before," Cashman said. "I think he's earned the right to take a shot at it, and he very well may be the guy. But we're not anointing him the guy."
Cashman said that a final decision on the Yankees' next closer may not be reached until the end of Spring Training, giving manager Joe Girardi and pitching coach Larry Rothschild plenty of time to sort through their options.
That likely does not come as a surprise to Robertson, who has done his best work in the eighth inning while securing just eight of 18 career save opportunities. He acknowledged at the conclusion of the season that while he would be excited for a chance to step into the retired Rivera's shoes, nothing has been assured.
"I don't feel like any of the passing of the torch has been done, because I don't know what's going to happen next year," Robertson said in late September. "I haven't been told anything."
Cashman said that he has heard from agents representing clients at the high end of the relief market, a group that could include hurlers like Joe Nathan, Grant Balfour, Brian Wilson and Fernando Rodney.
"I'm going to explore every option out there," Cashman said. "Our team has a lot of areas to fill, and the bullpen as a collective is weakened now with the loss of Mariano, the loss currently of Boone Logan as a free agent. We need to improve in that area. Whether that's big names or small names, we have to look at all of them."
Cashman said that he would like to retain Logan, a left-hander who had a 3.23 ERA in 61 appearances last season, but reiterated that the Yankees have many more holes to fill than just their relief situation.
He said that he needs to find 400 innings to fill out a pitching rotation behind CC Sabathia and Ivan Nova, eying two starting pitchers, and then also wants to secure insurance behind shortstop Derek Jeter and third baseman Alex Rodriguez.
Then, of course, there is the situation with free-agent second baseman Robinson Cano. Cashman said that there was no progress to report with Cano's representatives, though he did raise some eyebrows with a quote offered about the situation to the YES Network late on Monday.
"At the end of the day, I think from Robbie's perspective, it's all about the money," Cashman said on the network's Hot Stove show. "Whoever steps up and gives the most, I think will secure the player."
Cano reportedly requested a 10-year, $305 million contract from the Yankees, who have said that they will not go to that length of a deal. The Yankees are not expected to exceed a commitment of seven to eight years, potentially at $180 to $200 million.
"He loves the money," Cashman said on Tuesday. "I think we're going to have a substantial offer, but somebody might come in and have a much more substantial offer. That's just the way it works. ... He's in free agency and that's the feeling I get. It doesn't make it wrong at all.
"That's what makes the U.S. the greatest place in the world. We just have to compete for that. I feel very comfortable that we'll firmly compete for the player. The value we put on him and the value somebody else might put on him could be vastly different. If it is, we'll lose him."
The Yankees have been rumored to have early connections to outfielders Shin-Soo Choo and Carlos Beltran, two more of the big-ticket names on the free-agent market. Cashman said that he feels the need to explore the outfield market, given Curtis Granderson's rejection of a qualifying offer worth $14.1 million.
"If Granderson accepted, I would've been excited and happy and it would have been solved," Cashman said. "I have more pressing needs than outfield. In terms of a priority list, that's not as big a priority as some other aspects of the club."
The Yankees are also interested by some of the available catching choices, where Brian McCann is considered a prime free-agent target.
Cashman said he "absolutely" plans to tender a contract to Francisco Cervelli, giving the Yankees at least one in-house option for a position that also featured Chris Stewart, Austin Romine and J.R. Murphy behind the plate last year.
"On the defense and running the game, we're as good as we need to be," Cashman said. "There's no problem with our game calling, shutting down the opposing running game, the framing and all that good stuff. Defensively, we're exactly where we have to be. Offensively, we're short. If we can improve on that, great; if we can't, I'm still comfortable with shutting down the opponents' attempts to score on us."