FOXBOROUGH — The Patriots trimmed their roster from 90 players to 53 on Saturday, while assigning 10 players to the practice squad.

The roster had a limited number of open spots, and competition was high at numerous positions. The third tight end position, behind Rob Gronkowski and Dwayne Allen, was one of the tightest battles throughout camp. James O’Shaughnessy, acquired from the Kansas City Chiefs in late April, was expected to assume the role. But undrafted rookie Jacob Hollister opened the preseason with a seven-catch, 116-yard performance and gradually tightened the race for the position.

Hollister made the 53-man roster on Saturday. Perhaps the Patriots wanted a shifty, athletic end with strong hands, such as Hollister, to complement Gronkowski and Allen.

O’Shaughnessy was released Saturday. In late April, the Patriots acquired O’Shaughnessy and a sixth-round pick from the Chiefs in exchange for New England’s fifth-rounder.

In another close competition, swing tackle LaAdrian Waddle made the squad after sharing reps with Cameron Fleming at left tackle.

Overall, four undrafted free agent rookies made the 53-man roster: linebacker/end Harvey Langi, defensive lineman Adam Butler, offensive lineman Cole Croston, and Hollister.

The most notable cut was running back Brandon Bolden, who spent five seasons in New England. Although Bolden was the fifth or sixth running back in the rotation, he was an effective special teams player.

Running back D.J. Foster, another bubble player, was also cut after making the 53-man roster last year. Foster would have been retained mainly for his returning abilities after Cyrus Jones suffered a season-ending knee injury in the final preseason game.

Undrafted rookie Austin Carr, the leading receiver in the Big Ten last year, also was released. He led the Patriots with 153 receiving yards in the four preseason games.

Defensive lineman Geneo Grissom, who worked his way up from the practice squad to the active roster by last season’s end, was also released. The Patriots have limited pass rushers after Rob Ninkovich retired and Kony Ealy was released a week ago, but Grissom didn’t do enough to separate himself from the rest of the young guys at the position.

The Patriots waived offensive guard Ted Karras, who spent his rookie season on last year’s 53-man roster, and released offensive tackle Conor McDermott, a sixth-round draft pick.

Wide receiver Devin Lucien, on the practice squad last year, was released.

Hard day for all

Cut day is the most nerve-racking day of the preseason for the players fighting for a roster spot.

“Every day is serious, but this day is a little different,’’ veteran linebacker David Harris said. “People’s jobs are on the line. It’s the last day. It’s the bad side of the sport because guys put so much work in, and then at the end of the preseason some are told they are no longer needed. You have created a bond with them. That’s the business side with it.’’

Cut day is agonizing for everyone involved, from the players who are released, the coaches who tell them, and the veterans who watch their teammates pack up and leave.

“You feel for them,’’ Harris said. “They put so much work in to try to learn new playbooks and the way they can work around here. It’s sad I guess.’’

An influx of more than 1,100 free agents across the NFL became available on Saturday. The Patriots open the season against the Chiefs on Thursday, leaving both coaching staffs even less time to survey the market of players.

Bill Belichick says this period is similar to the draft in terms of discussing trades with other teams and surveying the free agent market. Belichick said it’s difficult to claim a player that none of the additional 31 teams is interested in acquiring, and trading is also tough because each side wants equal value.

“There are a lot of different circumstances that surround each player, and there’s a lot of potential trades that could happen, but when you really get right down to it, finding the right value, finding the right partner or finding the right situation is not that easy,’’ Belichick said.

“There’s going to be a few that happen, and there will be probably 10 times that many that are talked about that don’t happen.’’

Praise for Chiefs

On Saturday morning, Belichick started his press conference by saying this is “Chiefs week’’ before praising their roster and coaching staff.

The Chiefs finished the 2016 regular season 12-4, tied for the AFC’s second-best record behind New England’s 14-2 campaign. Belichick dissected the roster from top to bottom, saying Kansas City is “good at everything.’’

Andy Reid has led the Chiefs to the playoffs in three of the four seasons he has served as their head coach. He has split his two career meetings with the Patriots in his time with Kansas City.

Last year, rookie receiver Tyreek Hill, a first-team All-Pro, gave the Kansas City offense an entirely new dimension because of his blistering speed.

Belichick envisions Reid featuring Hill more in the passing game this season, but his unique skill set allows him to move him all over the field.

“Andy’s a very creative coach,’’ Belichick said. “I’m sure that they have a lot of different ways to use [Hill] and he’s a very versatile player, so he can run, he can catch, he can run as a receiver, reverses and plays like that. I’m sure they use him as a decoy. He’s a very explosive player that can affect all three levels of the defense.’’

On the other side of the ball, Kansas City’s physical front seven, combined with an opportunistic secondary, pose problems for any offense. The Chiefs allowed 19.4 points per game last season, seventh best in the league.

Cornerback Marcus Peters was named first-team All-Pro after recording seven interceptions, the second most in the league. Safety Eric Berry was also a first-team All-Pro last year.

“They blitz their inside linebackers occasionally, but they do a fair amount of five-man pressure, a fair amount of blitzing — certainly enough to keep you honest — and then they’re a very opportunistic secondary,’’ Belichick said.

Kansas City has been competitive with the Patriots in recent years. Three seasons ago, the Chiefs contained New England in a 41-14 drubbing in Kansas City. Two postseasons ago, the Patriots defeated the Chiefs, 27-20, during the divisional round in Foxborough.

Brad Almquist can be reached at brad.almquist@globe.com. Follow him on Twitter at @bquist13.