The three NFL trades completed this week, headlined by the Browns sending Joe Flacco to the rival Bengals, are expected to be a sign of things to come ahead of the league’s Nov. 4 trade deadline.

In a copycat league where teams constantly are striving to improve, general managers already have begun exploring additional trades, and based on recent years, there could be at least another dozen to come, league sources told ESPN.

Over the past six years, in the month of October leading up to the trade deadline, the NFL has had 88 trades — an average of just under 15 per year.

The list of trade candidates that executives and coaches believe could be available in the next few weeks features multiple high-profile players, including Kirk Cousins, Russell Wilson, Trey Hendrickson, Mark Andrews, Bradley Chubb, Alvin Kamara, Chris Olave, Breece Hall, Cameron Jordan and Riq Woolen. These players’ respective teams haven’t necessarily made them available via trade, but sources believe they eventually could be.

There were 18 trades completed both last year and in 2022. This increased number of deals stands in direct contrast to the nine trades made in the month leading up to the 2018 deadline, the eight made in 2017, the five made in 2016 and the four made in 2015.

The NFL trade deadline has become as busy as the deadlines in the NBA and Major League Baseball. The uptick in trade activity, in the opinion of many sources across the league, has come for a variety of reasons.

One reason is the younger and more aggressive GMs in the NFL. Many of the previous generation of GMs did not believe in trading players midseason and having new players come in to learn their systems.

But teams recently have had success trading for players ahead of the deadline, and seeing them enjoy success. In 2021, the Rams traded second- and third-round draft picks to the Broncos for Von Miller, who helped Los Angeles win Super Bowl LVI.

A season later, the Chiefs traded third- and sixth-round picks to the Giants for wide receiver Kadarius Toney, who helped Kansas City win the Super Bowl with a 65-yard punt return and a walk-in touchdown.

Teams have taken notice of the juice that a midseason acquisition can provide, and others have tried to duplicate the success of the Rams and Chiefs.

Just this past week, three of the four teams in the AFC North — Baltimore, Cincinnati and Cleveland — made trades Tuesday. The only AFC North team that didn’t complete a deal was the first-place Steelers, who are expected to explore upgrading their roster in the weeks ahead of the deadline.

The teams that are winning want to bolster their rosters — and their chances of making an extended playoff run. The teams that aren’t winning are willing to begin looking ahead to the next season and stockpiling draft-pick compensation to help replenish their roster.

Maybe it’s only fitting that, after a week of trades and with more expected ahead, Sunday marks the 36th anniversary of the Cowboys trading Herschel Walker to the Vikings for a package of players and picks that Dallas used to build its dynasty in the 1990s. The trade involved 12 draft picks and 18 players, and is one of the largest and most complicated not just in NFL history, but in sports history.

It’s hard to imagine that any NFL team could make a trade that significant ahead of the deadline. But GMs already are lighting up phone lines, digging into the available players and waiting to make their next move.