Owners of the Boston Red Sox are again eyeing an expansion at historic Fenway Park, with an estimated $4 million of plans for more dugout-area seating for fans, new suites, a right-field grandstand bar and a removable bullpen field wall so the park can fit regulation FIFA soccer and college ?football games.

Fenway Park’s existing stationary bullpen field wall would be replaced with a new removable wall to accommodate the regulation Federation Internationale de Football Association soccer pitch and college football field.

Red Sox principal owner John Henry also owns England’s Liverpool Football Club, a Premier League team. Fenway Park has hosted “friendly” exhibition matches featuring Liverpool and other European ?soccer giants.

The plans for a regulation FIFA pitch raise the question of whether Fenway’s owners could be open to hosting New England Revolution soccer games. The Kraft Group-owned Major League Soccer team is in a similar situation to the New York City Football Club, also an MLS team. Both are looking for new stadiums in their respective cities, and both have had problems finding a suitable place to break ground and build.

NYCFC currently plays at Yankee Stadium — the team is partly owned by New York Yankees owner Yankee Global Enterprises — while the Revolution play home games at the Kraft Group’s Gillette Stadium in Foxboro.

The Revs are looking at the Boston market, and conceivably home games at a newly expanded Fenway would give the team an opportunity to introduce itself to the very market it seeks to join.

Red Sox spokeswoman Zineb Curran declined to elaborate on the team’s plans filed with the city, telling the Herald, “It would be premature to discuss publicly any proposed changes to the ballpark at this early stage, as we are still reviewing options internally and awaiting review and analysis from various city organizations, including the Landmarks Commission.”

A Kraft Group spokesman said he couldn’t reach the Kraft family for comment.

The Sox also want to add 124 new dugout seats for fans — 110 in the infield and 14 in the outfield — by replacing the existing field wall and extending the dugouts, camera pits and seating by one row toward the field, according to documents filed with ?the commission.

The Red Sox’s planned right-field grandstand bar would replace grandstand seats in the top six to seven rows of Sections 5 to 7 and a portion of Section 4. It would include bar rails and stools, with seating for 92 people on a new concrete platform. The changes would result in a net loss of 367 grandstand seats, according to a Red Sox diagram.

“The seats … face toward the Green Monster rather than toward the field of play,” Red Sox documents state. ?“The views are awkward and not ideal.”

The four new “day of game” suites would be installed at the press level of the park, beneath the existing overhanging roof, in left and right fields.

The Red Sox also are seeking approval to replace Fenway’s deteriorating right-field foul pole — known as “Pesky’s Pole” in honor of late player Johnny Pesky — and install a new 15-foot-by-42.5-foot-long LED video board in place of the smaller Cumberland Farms sign in right field.