The conclusion of the draft is the unofficial “on” switch to the trading season. Teams can now redirect their attention and personnel toward the July 31 non-waiver deadline.

That 40 percent of the season is complete also supplies a significant sample size about the quality of a team. By this time last year, for example, Yankees general manager Brian Cashman had seen enough of his aging roster in decline to be lobbying his bosses to be sellers.

This year’s team is better than anticipated. Cashman will take further time to read the staying power and needs of this group. But all indicators are the Yankees will be in buy mode.

At present, the Yankees definitely will be looking for a lefty reliever, probably a starter and — if the bad injury news on Greg Bird does not reverse — a first baseman. I think the Yankees will try to solve third base internally, perhaps with Gleyber Torres, if they look to do better than Chase Headley.

Cashman has been the Yankees’ general manager for two decades, long enough to establish patterns that should help provide clues about how he will proceed, and that by the end will lead me to believe a strong focus will be on the White Sox’s Jose Quintana:

1. Cashman will deal from strength. For example, in recent years, the Yankees had catching depth in the system, and used Jesus Montero to get Michael Pineda, Francisco Cervelli to land Justin Wilson (who became Luis Cessa and Chad Green) and John Ryan Murphy to obtain Aaron Hicks.

The Yankees’ system is deeper than any time in Cashman’s tenure, so he could trade for any position. But the team is particularly deep in middle infielders (Gleyber Torres, Jorge Mateo, Thairo Estrada, Tyler Wade, Nick Solak, Kyle Holder, Hoy Jun Park) and starting pitching (Cessa, Green, Bryan Mitchell, Domingo Acevedo, Domingo German, Chance Adams, Albert Abreu, Freicer Perez and Zack Littell).

2. Cashman will be mindful of the 40-man roster. The Yankees dealt with a crush last year and lost four players in the Rule 5 draft. They got three back, but that San Diego continues to retain the fourth, catcher Luis Torrens, on the major league roster though he had just 57 plate appearances all year and was hitting .170 is symbolic to the Yankees that tanking organizations will take unprotected talent and keep it all season even if the player is not ready for the majors.

Part of trading players such as Ben Gamel, James Pazos and Nick Goody was because of the evaluation that there were better prospects ahead of them and the 40-man crush eventually would force them off the roster.

This is not a full list, but these prospects must be put on the 40-man roster between now and Nov. 20 or risk being exposed to the Rule 5 draft: Torres, Abreu, Acevedo, Wade, Littell, Estrada, Clint Frazier, Dustin Fowler, Ian Clarkin, Billy McKinney and J.P. Feyereisen (Mateo already is on the 40-man).

Chris Carter, Matt Holliday, Tyler Clippard, CC Sabathia, Masahiro Tanaka and Michael Pineda can be free agents, but some might be retained or replaced by veterans. Players such as Tyler Austin, Rob Refsnyder and Mason Williams will be vulnerable to losing spots.

Still, the Yankees will have to worry enough about getting a good group of prospects on the 40-man that they will use some of those eligible in deals to begin the cleanse sooner.

3. Cashman will trade with whom he is comfortable. There is a large human element here, and you more likely will deal with people you trust, but also executives who evaluate talent similarly so that is time is not wasted. Few things bother executives more than when they feel the guy on the other end of the cell is trying to rob them rather than make a fair deal.

For example, because of the Yankees-Red Sox dynamic, Theo Epstein did not make trades with the Yankees when he ran Boston’s baseball operations. But Cashman-Epstein have done three significant deals since Epstein went to the Cubs, including two at the deadline. Last July, the Yankees appreciated that Epstein knew immediately what kind of prospects/package it would take to acquire Aroldis Chapman.

Conversely, Dayton Moore has been the Royals’ GM since 2006, and the only trade he has made with Cashman was a small Wilson Delgado-for-Nick Ortiz deal in 2000. It doesn’t mean the Yankees wouldn’t be in on Eric Hosmer, Jason Vargas or Mike Minor if the Royals were selling, just that these teams don’t match up often.

Cashman’s most familiar partner has been Jerry Dipoto in Arizona and now Seattle, but the teams do not line up well for a deal now. Many club executives have complained to me that the Pirates are hard to deal with on trades, but Cashman has made plenty with his counterpart, Neal Huntington, so Gerrit Cole and/or Tony Watson could become interesting.

The Yankees always have had a strong relationship with Al Avila, now the Tigers’ GM, so perhaps Wilson could be back in play.

And though Billy Beane is one of Cashman’s best friends in the game, the two partner infrequently on deals, though I would think the Yankees would inquire on lefty Sean Doolittle and perhaps Sonny Gray.

Lastly, the Mets and Yankees have not made a player-for-player deal since Mike Stanton-for-Felix Heredia in 2004, but if the Mets become sellers, the Yankees like Jerry Blevins.

4. Cashman will not forsake the future. He is proud of the base of young talent the Yankees have assembled, and Hal Steinbrenner is now fully on board for this approach, especially because he wants the Yankees to get under the $197 million luxury tax next season.

Thus, Cashman will keep salary in mind when making acquisitions — so expensive pieces such as Justin Verlander or Zack Greinke probably are out. Also, with Pineda, Sabathia and Tanaka possible free agents, the Yankees likely will prioritize starters who are not free agents after the season, such as Vargas or Yu Darvish. In addition, if Cashman is going to cede high-end prospects, he will want the return for more than two months.

All of this is why — though the Yankees and White Sox have not made a trade since 2009 — Quintana makes sense, as long as Yankees scouts are comfortable his high ERA reflects more on being constantly in trade rumors while on a poor team rather than a decline in stuff. Also, Cashman would have to be comfortable with Quintana’s past, because in recent years the Yankees GM has tended to shy away from players with PED histories, and the Mets released Quintana in the minors after he failed a 2007 test — which actually led to him signing to play in the Yankees’ minors.

He would cost the kind of prospects who would help alleviate some 40-man roster crunch — this is made up by me: Adams, Frazier, Mateo and Estevan Florial. He is just 28 and lefty. Plus, he is under control through 2020, and how his team-friendly deal is structured Quintana would cost just $5.3 million toward the luxury tax payroll next year.

The Yankees would have plenty of competition for Quintana, notably from the Astros. But a lot of Cashman’s history points toward him as a real possibility.