Even though the Nationals are 23-15 and in first place in the National League East six weeks into the season, some fans still wonder: When is Trea Turner coming up? The fact that Danny Espinosa is hitting .212 with a .630 OPS only fuels the question. Turner is the Nationals’ top position player prospect and their potential shortstop of the future who is hitting .319 with 14 stolen bases and a .844 OPS at Class AAA Syracuse. It is the backup quarterback syndrome: Fan bases always dream of the next option.

Turner’s case involves various factors, and one consideration is the service time clock. The Nationals are in the win-now mode of their team history, so if they were a Trea Turner away from being a winning team, it’s easy to imagine General Manager Mike Rizzo calling for the speedy prospect now. But with Espinosa’s stellar glove and struggling bat, the Nationals are winning now.

Yet if the Nationals want to ensure they can keep Turner longer, the soonest they could call him up  if they wanted is at least early June to be safe. In order to become a free agent, a player has to accrue six years of service time. Although a baseball season is 183 days, 172 days equals one full year of service time.

Turner accrued 45 days last season in the majors — evidence the Nationals weren’t concerned about service time. So to ensure he doesn’t accrue a full year of service time this year, he needs to spend 57 days in the minors. That would mean he could come up on May 30, stay on the roster the rest of the season and only have 171 days accrued. As a result, the Nationals would have a so-called seventh year of control over Turner, through the 2022 season.

Some teams — the Cubs with Kris Bryant and the Phillies with Maikel Franco — have had to deal with service time manipulation grievances filed by players because they fell a day or two, respectively, short of gaining a full year of service time. So if a team wanted to avoid any appearance of manipulation, holding off even longer to be safe may help their cause.

In the past, the Nationals have called up their top prospects after the extra year cutoff. The Nationals got the so-called seventh year of control over Stephen Strasburg, Drew Storen, Anthony Rendon and Bryce Harper. The Nationals have, however, shown a willingness to pay players. If a player ranks in the top 22 percent of players with between two and three years of service time, they are eligible for a fourth year of arbitration as a “Super 2” player. The Super 2 deadline changes each season but it is generally around mid-June. Storen, Rendon and Harper were all Super 2 eligible players.

This isn’t an argument for or against Turner’s call-up. Turner, 22, is off to a strong start at Syracuse. He is improving, too. His strikeout-to-walk ratio is better; he has fanned 29 times and walked 15 times in 155 plate appearances. Last season between two minor league levels, he struck out 97 times and walked 38 times in 500 plate appearances. Class AAA success, however, doesn’t always guarantee major league success.

By some accounts, Turner’s defense is improving this season but it is still one of his areas of needed work. He has committed six errors in 32 games at shortstop, about the same rate as last season’s 21-error season. He has looked more comfortable with his hands in the field.

Some Nationals officials believe Turner simply needs to play and aren’t concerned about calling him up until he is ready. Even though Turner excelled and tore through the minors, last season was his first full professional season. He was traded, played for three teams and reached the majors. He has played little overall. Including 35 appearances at Syracuse this season, Turner has played in only 220 minor league games.

When Turner does come up, the Nationals would likely prefer a clear path to starting. He wouldn’t come up for a few weeks, play and then sit on the bench. If he gets called up, he is likely up to stay. Harper came up in late April 2012 and has been a mainstay since. Other than a brief two-week stint while the Nationals were injured in April 2013, Rendon came up in June of that year and stayed up for good.

The Nationals have won for a month and a half with Espinosa. His OPS is 21st out of 28 qualified major league shortstops. If the rest of the Nationals lineup is hitting like it should — which isn’t the case now — Espinosa’s bat shouldn’t draw so much attention. He is a solid baserunner and a standout defender with a strong arm that helps Daniel Murphy, his less defensively-gifted double play partner. The Nationals pitching staff has benefited as a result.

Over the past week, Espinosa has looked better at the plate; he is 6 for 22 with a home run. And before the weekend series against the Marlins, Manager Dusty Baker said he hadn’t told Espinosa not to look over his shoulder but told him to think positively about improving.

“It’s up to him to create job security,” Baker said. “It’s not up to me to tell him. It’s not like he’s a kid. I just told him that he had to remain positive, put together good at-bats and, above all, you’ve got to have confidence. Myself, [assistant hitting coach] Jacque [Jones] and [hitting coach] Rick Schu, we just try to stress to him to stay through the zone and he doesn’t have to hit the ball out of the ballpark to help this team and be successful. Danny has taken it upon himself to work hard and I gotta give him full credit. Even when he wasn’t getting hits, he was hitting the ball pretty good.”