One of the bigger storylines among Monday morning quarterbacks was Chicago Bears coach John Fox’sdecision to challenge a play that not only reversed a catch-and-run to the 1-yard line but also gave possession to the Green Bay Packers in an eventual 23-16 loss Sunday.

The line for pulling the red flag is a delicate one, and Ravens coach John Harbaugh said the thought process for challenging a play involves a plethora of factors.

“The biggest thing is getting a look at it and knowing that you have the look that will overturn it. That’s the key,” he said during his weekly conference Monday. “Sometimes you’re able to get that, and sometimes you’re not. On the road, it’s way more difficult than it is at home to get that. But by the same token, it’s what the TV cameras who are doing that game are able to get. That’s what the replays are based on. You can know you’re right, but you could also say that I don’t think they have a look at it and know that you’re not going to get it. Our basic rule is, if we don’t believe there’s a good look at it, we’re not going to throw the flag unless it’s a situation where we don’t have much to lose.”

For Fox and Chicago, the challenge proved detrimental. Running back Benny Cunningham was ruled to be short of the goal line, inviting Fox to argue that he had scored. But replays showed that Cunningham actually lost the ball, which hit the pylon. Officials ruled the play a fumble out of the end zone and gave possession to Green Bay in the second quarter.

Harbaugh, who is 2-for-2 on replay challenges, acknowledged that there are times when tossing a red flag even in the face of a loss is not such a bad move.

“There are other situations where you might throw the flag just because it doesn’t hurt you to throw the flag,” he said. “It could be late in the game and you were going to take a timeout anyway. There’s a little bit of a questionable call and you might throw the flag instead of taking a timeout just in case you’re going to see something that may make you want to challenge it if you’re going to call the timeout anyway — knowing that you don’t really have anything or that you don’t have anything yet and you’re hoping for something. That might be a situation where you lose, but you’re willing to lose there because you were going to take the timeout anyway.”

Boyle eager to return:A toe injury on his left foot forced Nick Boyle to sit out the Ravens’ 23-20 loss to the Tennessee Titans on Nov. 5 — the first game he’s missed this season — and the tight end is champing at the bit to return as quickly as possible.

Boyle, 24, started seven of the first eight games and has caught 18 passes for 138 yards. Boyle said he injured the toe in a 40-0 rout of the Miami Dolphins on Oct. 26.

“I’m not used to missing games, and it’s not the most fun thing to be in the training room because you feel like you’re missing out during practices,” he said. “That’s something that I hate to do. I want to be out there; I want to be playing. But it’s important for me to get healthy and get ready to play as soon as I can.”

Homing in on Hundley:The defense will get its first look of rookie quarterback Brett Hundley, who has replaced injured Aaron Rodgers (broken collarbone). Hundley, the organization’s fifth-round pick in the 2015 NFL draft, is 1-2 as a starter this season, but he completed 18 of 25 passes for 212 yards and one touchdown in Sunday’s win in Chicago.

Harbaugh sounded impressed with what he has seen from Hundley.

“He looks like he’s plugging right into the offense,” Harbaugh said. “It seems like they’ve kind of brought him along, and he runs the Green Bay offense that they’ve been running for a number of years. He’s running the offense in his way. It looks like he’s getting better every week.”

End zone:The team waived running back Bobby Rainey Jr. to make room on the active roster for offensive tackle Andrew Donnal. Donnal, 6 feet 6, 316 pounds, was selected by the Los Angeles Rams in the fourth round of the 2015 NFL draft and started six games in 2015 and 2016 before being released Saturday. The release of Rainey — who returned a kickoff 96 yards for a touchdown in a 27-24 overtime loss to the Bears on Oct. 15 — suggests that wide receiver Michael Campanaro is poised to regain the primary kick-return role. Campanaro has missed the past two games because of a shoulder ailment. … Former Ravens linebacker Dannell Ellerbe joined the Philadelphia Eagles on Monday. A free agent since the New Orleans Saints released him over the summer, Ellerbe — who spent four years with the Ravens — could fortify a defense that lost linebacker Jordan Hicks for the season because of a torn Achilles tendon.

edward.lee@baltsun.com

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