WASHINGTON — During a call over the winter, as the Washington Nationals vetted potential free agent signings to stabilize their starting rotation, pitching coach Simon Mathews sat in silence and wondered whether the man on the other end of the line understood that he had yet to actually secure a job. How else to explain the player’s brutal honesty about his own struggles?“I remember thinking, like, man, if I was his agent, I’d tell him to shut the f— up,” Mathews said. “Just because he was, like, wide open.”Miles Mikolas sounded like a National already. That candor got Mikolas — and later, fellow right-hander Zack Littell — to Washington as reinforcements for a rotation in need of depth. The enduring spirit of their honesty helped them figure it out when their seasons began to go awry.At a fundamental level, the Nationals’ new brass believes there is no such thing as a finished product. That holds true even for two arms in their 30s, one of which gave the Nationals seven scoreless innings on Sunday in a 10-1 victory over the Seattle Mariners. Mikolas’ effort handed the Nats their eighth series win in their last 10 tries.Though Littell’s last outing was a clunker in Friday’s series opener, it came after a strong stretch.The Nationals are 37-35, one game out of the NL Wild Card, stabilized by a pair of pitchers who had an ERA over 7.50 in April but were put in the right environment to figure it out.Coaching and candor — and insights from biomechanics — unlocked some answers. In this case, the solution was to recreate the past. Littell spent the winter chasing better metrics on two pitches he used sparingly. Mikolas spent the last two seasons chasing new ideas. Neither had found much success.But now both are confident in the path ahead.“We’re digging into it, like, what can I do better,” Littell said. “It’s like, ‘Well, let’s get back into what you do well.’”As for Mikolas? He needed to pitch in a manner antithetical to baseball’s modern philosophy.“We’re gonna throw a f—ing pile of fastballs down and away, buddy,” Mathews said. “Welcome to 1978.”Mikolas couldn’t ‘Shut the f— up’The decline happens slowly, Mikolas said, so much so that he almost didn’t realize it until it was too late. From 2018 through 2022, he pitched to a 3.46 ERA while making over 100 starts. In the three years that followed, he provided innings, but his ERA hovered around 5.00.Mikolas’ track record and demeanor allowed both him and the Nationals to be honest about what they could expect from one another. Mikolas could give the Nats moxie, innings and more upside than they bargained for at $2.25 million. The Nats could give him some runway to figure it out.