The day will come when Patrick Mahomes is on his last legs, playing his final NFL game, struggling to do the things that came easy for him in his 20s.

Ben Roethlisberger was never able to do some of the things Mahomes can, but for many years he played at a Hall of Fame level. It never lasts forever, not even for the greats.

The last look at Roethlisberger in a Pittsburgh Steelers uniform wasn't pretty. He struggled again to throw. The Steelers battled but eventually the Chiefs wore them out. Mahomes made huge plays with his prodigious arm talent. The Steelers could not keep up.

Mahomes had five touchdown passes with less than six minutes expired in the second half as the Chiefs poured it on and blasted the Steelers 42-21 in an AFC wild-card playoff game. The Chiefs scored so much, they announced in the fourth quarter they ran out of touchdown fireworks. Pittsburgh barely got into the playoffs, sneaking in when things went their way in Week 18. Everything was difficult for them and Roethlisberger all season.

The season is finally over, and with it, Roethlisberger's career is likely done as well. Very few players get a satisfying ending.

Steelers offense struggles

The numbers at halftime told the story. The Steelers had 44 yards and two first downs. Pittsburgh had 14 pass attempts and 13 net passing yards. Diontae Johnson had a couple drops that didn't help, but it's hard to blame what we saw on him. Roethlisberger's play started to tail off in the second half of last season and he never came close to getting it back. That's what happens to most NFL players in their late 30s, if they're lucky enough to last that long.

For a while, the Steelers seemed like they could stay in the game. The defense played hard from the start. T.J. Watt tipped a pass that was intercepted. A botched wildcat handoff led to a fumble and Watt recovered and scored for a 7-0 Steelers lead. There was some hope in that moment.

Eventually Mahomes was going to get it going. The Chiefs scored 21 points before the end of the half. In the final seconds before halftime Mahomes rolled right and with the flick of his wrist he hit Travis Kelce downfield. Kelce turned it up and scored a 48-yard touchdown. That gave Kansas City a 21-7 halftime lead. Mahomes had 241 yards at halftime. Roethlisberger had 24.

Mahomes has a rare talent. It helps to be 26 years old and in his athletic prime. Roethlisberger was a different quarterback in his prime, shrugging off defenders to keep plays alive and delivering deep downfield. It has been a while since he could do that. This is a stripped-down version, getting rid of the ball like a game of hot potato to avoid getting hit. Roethlisberger had a few nice second-half throws including a couple touchdowns to avoid a Dan Marino-type ending, when the Miami Dolphins lost 62-7 in his final game.

There will be a time when the crazy passes Mahomes attempts won't be possible for him anymore. There will be someone much younger on the opposing team who is making those plays, running Mahomes and his team off the field in a big game as Mahomes' career winds down. That's just how the NFL goes.

Chiefs blow out the Steelers

The Chiefs have been on a roll for a while, and Sunday night was an extension of that. They have won 10 of 11 since a rough start to the season. Their win sets up a fascinating matchup next weekend against the Buffalo Bills, who were practically perfect in a blowout win over the New England Patriots on Saturday.

The Chiefs looked sharp against the Steelers after a slow start. Versatile running back Jerick McKinnon continues to emerge as a big threat late in the season. Kelce made some huge plays, and even had a touchdown pass in the fourth quarter. Offensive lineman Nick Allegretti scored on a tackle-eligible play with 10:13 left, on Mahomes' fourth touchdown pass, and that put the Chiefs ahead 28-7. There was no way Pittsburgh was coming back. At that point, seven-of-seven Steelers possessions ended in punts and they hadn't run a play in Chiefs territory. Najee Harris lost a fumble on the Steelers' first play after Allegretti's touchdown, which led to Mahomes' fifth touchdown pass, one to Tyreek Hill. Sunday night had a lot to do with the Steelers offense, but the Chiefs defense still deserves credit for playing well and holding Pittsburgh to almost nothing.

There hasn't been an official announcement about what comes next for Roethlisberger, but he celebrated Pittsburgh's home finale as though it was a foregone conclusion that it was his last home game. Retirement seems likely. It seems crazy to think about Mahomes being in that stage of his career, reminiscing on nights like Sunday when he threw for a bunch of touchdowns in a playoff win. But it will happen for him too.