SEATTLE -- After making his third trade in the past eight days and 23rd since the start of the past offseason on Friday, Mariners general manager Jerry Dipoto certainly isn't ruling out another deal before Monday's non-waiver Trade Deadline. But don't hold your breath on a Sonny Gray-type blockbuster.

"I don't think that's ever been very likely," Dipoto said, noting the extremely high return being sought for elite starting pitchers. "We've been very conscious of preserving our talent pool."

In other words, Dipoto isn't ready to literally give up the farm for a starter at this juncture, instead moving to deepen the rotation pool for this year and beyond with trades for versatile right-hander Erasmo Ramirez from the Rays and lefty prospect Marco Gonzales from the Cardinals, along with giving the bullpen a boost with veteran right-hander David Phelps via trade with the Marlins.

Is it possible more deals could be done?

"Sure. We're always open," Dipoto said. "The phone is never very far from me, and there are areas we can improve, so we'll keep our ears to the street. The likelihood is there probably isn't going to be another move, but I would have told you that two days ago as well."

Ramirez, who was acquired in exchange for reliever Steve Cishek on Friday, will move into the rotation and start on Tuesday in Texas, taking the place of rookie Andrew Moore . Gonzales may not be far behind after impressing Dipoto and the Mariners' brass with his showing for Triple-A Tacoma on Tuesday.

"He looked about as big league-ready as a Triple-A pitcher could be," Dipoto said. "We were very encouraged by what we saw. We also don't want to put him in a situation where he's having to come in and be the savior. He's throwing particularly well in Triple-A. Eventually we'll see him here in 2017, it's just a matter of whether that's in August or September."

Dipoto gave up highly regarded outfield prospect Tyler O'Neill to get Gonzales, and he gave up four prospects to get Phelps. He noted the haul would be much steeper than that to land one of the top veteran starters on the limited trade market. So while some clamor for the Mariners to go "all in" and give up top prospect Kyle Lewis and a lot more to get in the running for A's ace Gray or others, he looks at the Mariners' roster and continues seeing a bigger picture.

Dipoto notes that while Robinson Cano , Nelson Cruz and Felix Hernandez are in their 30s, the Mariners have surrounded them with Jean Segura , Kyle Seager , Ben Gamel, Mitch Haniger, Mike Zunino, Guillermo Heredia , James Paxton and Edwin Diaz all in their 20s.

"We don't think we're on a jet getting ready to crash into the Earth," he said. "We think we're a sustainable product. We like our team. We're built around a core of players like Robbie and Nelson and Felix and Kyle, and there's a reason why you've heard me talk over the last two years about raising the floor. I think we've effectively raised the floor.

"We've got the second and third leading hitters in the American League [in Segura and Gamel]. We have a group of young players around the field that are doing positive things and a bullpen that is coming together nicely and now especially with some of the more-recent additions is sustainable and diverse. And we need to address our starting pitching.

"But in order to get starting pitching, you draft it, you cultivate it, you grow it or you sign it as free agents. Because trading for starting pitching is ridiculously expensive and we're aware of that."

Greg Johns has covered the Mariners since 1997, and for MLB.com since 2011. Follow him on Twitter @GregJohnsMLB.