Four days after they added Ameer Abdullah to their roster, the Vikings returned from their bye week and practiced for the first time Monday. The former Lions running back adds depth to their backfield while providing the former second-round pick with a fresh start.

Abdullah, whom the Vikings claimed off waivers Nov. 8, comes to the Vikings hoping to reboot his career. He ran for 552 yards a year ago, starting a career-high 11 games and scoring five touchdowns, but became expendable when the Lions used a second-round pick on Kerryon Johnson last spring.

“Life is amazingly unpredictable,” Abdullah said. “It’s a great team, great culture, great atmosphere to be joining. Ironically, it’s in the same division. Everything happens for a reason, so I’m really excited to be here in Minnesota.”

Abdullah, who said he trained with Vikings linebackers Anthony Barr and Eric Kendricks in the offseason, figures to start by helping to fill the No. 3 running back role after Roc Thomas’ hamstring injury led to his being moved to the practice squad. The Vikings still have Mike Boone on the active roster, and should have a fully healthy Dalvin Cook to pair with Latavius Murray heading into Sunday night’s game in Chicago.

“I’m coming in with no expectations,” Abdullah said. “You’ve got to live in whatever day you’re in.”

New year, new offense

Athleticism is one aspect of second-year Bears quarterback Mitchell Trubisky’s game that stands out to Vikings safety Harrison Smith. But Trubisky has another weapon in his arsenal that has helped him improve: the Bears’ scheme under first-year coach Matt Nagy, who learned from Andy Reid in Kansas City.

In two losses against the Vikings last season as a rookie, Trubisky completed just 32 of 61 passes (.525) for 306 yards, one touchdown, one interception and a lost fumble. On Sunday night, the Vikings are expecting a better-designed Bears attack, one that has averaged 29.9 points per game this season.

“They’re doing a lot of cool things,” Smith said. “Some things that are going around the league, too. Offenses are very explosive this year; creative stuff, getting the ball into their playmakers’ hands.”

Trubisky threw for 355 yards and three touchdowns against Detroit on Sunday.

Morgan may be out

The Vikings offense could be without one of its best blockers Sunday night in tight end David Morgan, who suffered a knee injury against the Lions.

Morgan declined comment Monday. Rookie tight end Tyler Conklin, who has played 73 snaps on offense (12 percent of the Vikings’ total), likely would see a larger role should Morgan be held out.

The Bears’ defensive front, featuring end Khalil Mack and linebacker Roquan Smith, is considered one of the NFL’s best. Chicago ranks in the top five in points and yardage allowed, specializing in a run defense that surrenders just 3.6 yards per carry.

A poor history

A victory Sunday would give the Vikings back-to-back wins at Soldier Field for the first time since 1999-2000. The Vikings are 3-14 in Chicago during that stretch, including last year’s 20-17 Monday night win.

The Vikings are 2-2 out of the bye week under coach Mike Zimmer.