Frankly, the 49ers never should have traded DeForest Buckner to the Colts in the first place.

The 49ers never have been able to replace him. Both Arik Armstead and Javon Kinlaw are now gone, and Javon Hargrave is on Injured Reserve with a torn triceps. Now the 49ers’ starting defensive tackles are Maliek Collins and Jordan Elliott, who are serviceable but unspectacular.

And suddenly, defensive tackle is one of the thinnest positions on the roster.

“Internally, there have been discussions about going after marquee players and more affordable, less glamorous options alike,” writes Michael Silver of The Athletic. “Could three-time Pro Bowl selection DeForest Buckner, the team’s 2016 first-round pick who was dealt to the Indianapolis Colts after the 2019 season, be reacquired via trade?”

Buckner his missed all but the first two games this season with an ankle injury. This week, the Colts list him as questionable to play. Perhaps they’d be willing to trade him because he’s getting older and he’ll be expensive the next two seasons. Which means the 49ers might not be able to afford him.

“(Trading for Buckner) seems unlikely,” writes Silver, “but another key player from that 2019 team, D.J. Jones (now with the Denver Broncos), might be a realistic target.”

Jones will be a free agent after this season and he’s relatively affordable, so he would be a good addition, particularly to a run defense that has struggled all season.

Expect the 49ers to add a defensive lineman at the trade deadline if they beat the Cowboys this Sunday night.

If they lose to Dallas, the 49ers could be trade deadline sellers.