WINNIPEG -- Jon Gruden says he was ready to put his Oakland Raiders on the field in Winnipeg for an pre-season game with the Green Bay Packers, but the head coach had to quickly make some adjustments. So, too, did the players and the NFL.

The teams ended up playing on a field Thursday that was shortened because of concerns over the condition of the end zones at IG Field.

Raiders kicker Daniel Carlson booted a 33-yard field goal with eight seconds remaining in the game for a 22-21 victory.

"I'm not going to make a big deal about the field," Gruden said. "We liked the field. We thought the field was perfectly ready to roll. You'll have to ask Green Bay about that."

The regular 100-yard NFL playing field was shortened to 80 yards. The end zones were marked with bright, orange pylons at the 10-yard lines and there were no kickoffs.

"The field met the mandatory practices for the maintenance of surfaces for NFL games based on an inspection yesterday," the NFL said in a statement.

"Concerns arose today surrounding the area where the (Winnipeg) Blue Bombers' goal posts were previously located. The 10-yard line will function as the goal line at this game. In lieu of kickoffs, the ball will be placed at the 15-yard line."

Before warmups, game officials and staff from both clubs were on the field examining the patches of turf that covered the spots where the goal posts for 110-yard CFL games were removed, which were in the playing surface of the NFL end zones.

The home field of the Bombers had been converted for the smaller NFL size, with new painted lines, goal posts located at the back of the new end zones and turf added all around the field to cover the regular asphalt.

Packers head coach Matt LaFleur decided to sit 33 players, including many starters such as star quarterback Aaron Rodgers and running back Aaron Jones. Rodgers hasn't played in the pre-season, including last week when he had tightness in his back.

Oakland didn't play starters such as quarterback Derek Carr or new receiver Antonio Brown.

"We were going to have all our starters play, and it was just one of those deals," LaFleur said. "We certainly have all played on much worse surfaces in our life, but it was just one of those deals where they weren't playing their starters and so we just decided to sit them."

Promoter John Graham, president of On Ice Entertainment Ltd. that was in charge of the field conversion, told The Canadian Press in a text message that he'd "like to wait" before making a comment.

Winnipeg Blue Bombers president and CEO Wade Miller was unavailable for comment.

Canadian-born Raiders tight end Luke Willson said he was unaware of concerns about the field until players were told it was being shortened right before the game.

"Even right now, I don't know exactly what it was," said Willson, who hails from LaSalle, Ont.

He does know he enjoyed the crowd of 21,992 fans, many dressed in colours of both teams.

"I was very impressed," Willson said. "I kind of heard some rumblings that it wasn't going to be packed. I know it wasn't sold out, but that being said, for two teams that aren't from Winnipeg, I thought there was a very good turnout today.

"Being a pre-season game at that, I thought the crowd got loud at times, they had the wave going, they seemed to be into it."

Packers quarterback Tim Boyle said he checked out a turf-covered spot during warmup.

"It was just a little raised," Boyle said. "But it's something you don't really want to play around with, especially guys who, this is their living. This puts food on the table for them, so you don't want to mess around with injuries."

Boyle completed 16-of-25 pass attempts for 191 yards with touchdown passes to Trevor Davis and Jake Kumerow.

Winnipeg native and fan Chris Sellar, who was sporting a Packers jersey, cheesehead hat and a green plaid kilt, said the field looked "odd."

"My disappointment is that the starters they promised were playing didn't play, Aaron Rodgers, Aaron Jones."

LaFleur had said this week Rodgers would be a game-time decision. The 15-year veteran pivot did take part in the warmup.

"But they promoted it like they were all going to play," Sellar said. "For folks who paid $300 a seat, I'd be pretty disappointed."

Sellar and a friend bought the reduced end-zone tickets for $75 plus taxes and fees, for a total of $94.25 each.

The event had drawn controversy since ticket prices were announced in June.

Tickets were $75 to $340 before taxes and fees. The limited cheapest upper-deck ones sold out fast. Up to 6,000 end-zone tickets were recently reduced through a sponsorship deal to $75 from $164.

Green Bay led 21-10 at halftime, which featured Winnipeg band Attica Riots.

Oakland quarterback Nathan Peterman had squeezed the score to 21-19 when he threw a 17-yard TD pass to De'Mornay Pierson-El at 9:12 of the fourth. A two-point pass attempt was intercepted by Packers linebacker Brady Sheldon.

The game was the first NFL contest in Canada since the Buffalo Bills completed a run of eight games in Toronto with a regular-season clash against the Atlanta Falcons in December 2013.