NFL predictions: Playoff implications for 49ers vs. Colts on Monday Night Football from proven model

It would be nearly impossible for the San Francisco 49ers to miss the playoffs at this point in the 2025 NFL season. The same was being said about the Indianapolis Colts eight weeks into the campaign, but here we are.

The Colts were sitting pretty in the postseason picture after winning seven of their first eight games, but the wheels have fallen off the wagon since then and their playoff hopes have significantly diminished. Indianapolis will find itself in an almost must-win situation when it hosts San Francisco at Lucas Oil Stadium in Week 16 at 8:15 p.m. on Monday Night Football.

The 49ers (10-4) could have their ticket to the postseason already punched by the time they take the field, as they would secure a berth if the Detroit Lions lose to the Pittsburgh Steelers on Sunday. Should Detroit win that contest, San Francisco could earn a playoff spot by defeating Indianapolis.

Things are much convoluted for the Colts, who have lost four consecutive games, five of their last six and their starting quarterback for the year. Already playing with a fractured left fibula, Daniel Jones -- who was having an impressive comeback season -- suffered a torn right Achilles tendon in the team's 36-19 loss to the Jacksonville Jaguars in Week 14, ending his campaign.

Backup Riley Leonard replaced Jones in that contest and injured his knee, leaving Indianapolis scrambling ahead of its Week 15 matchup against the Seattle Seahawks. With 2023 fourth overall draft pick Anthony Richardson still on injured reserve with a fractured orbital bone, the Colts coaxed Philip Rivers out of retirement and fed him to the wolves, AKA Seattle's top-five defense.

Indianapolis' offense registered just 220 total yards and the 44-year-old Rivers, who last played in the NFL with the Colts in 2020, completed 18-of-27 pass attempts for 120 yards with a touchdown and an interception. The eight-time Pro Bowler still had the team in position to win as it took a one-point lead in the final minute of the fourth quarter, but Seattle's Jason Myers set a franchise record with his sixth field goal of the game with 18 seconds remaining and the Seahawks held on for an 18-16 triumph.

The loss kept the Colts in third place in the AFC South and dropped them to eighth in the conference standings. Despite their recent misfortunes, there's a possibility they enter Monday night with their postseason destiny in their own hands.

On Sunday, the AFC South-leading Jaguars visit the conference-best Denver Broncos, the Los Angeles Chargers take on the Cowboys in Dallas and the division-rival Houston Texans host the Las Vegas Raiders. If either Jacksonville, Los Angeles or Houston loses, Indianapolis could soar right into the playoffs by winning its final three games.

SportsLine's Inside the Lines team believes that even with a loss in Week 16, San Francisco is a virtual lock for the postseason, even if passing the Los Angeles Rams and Seahawks to win the NFC West title is far-fetched. According to the ITL team's model, which simulates every NFL game 10,000 times, the 49ers currently have more than a 96% chance to make the playoffs, and they would drop by less than 3% should they fall to the Colts.

The model says Indianapolis' prospects for a postseason berth are less than 14% entering Monday's contest and fall below 6% with a setback against San Francisco.

The road ahead certainly is a tough one for the Colts, and even though they won't be eliminated from playoff contention with a loss on Monday, it will make qualifying even more difficult. But if they receive help from just one of the three aforementioned teams on Sunday, their only concern will be posting victories against the 49ers, Jaguars and Texans in their final three games.

Indianapolis owns a 27-19 record in the all-time series against San Francisco and has won each of the last five meetings, including a 30-18 triumph in 2021. Jonathan Taylor, who leads the NFL in rushing with 1,443 yards, ran for 107 and a touchdown in that contest while receiver Michael Pittman Jr. made four catches for 105 yards and a TD.

San Francisco is a 5.5-point favorite against Indianapolis in the latest NFL odds at DraftKings. The ITL team's model is predicting a 28-24 triumph by the 49ers, which would give them a playoff berth if one wasn't already secured by a Detroit loss on Sunday and put an enormous damper on the Colts' postseason hopes.