Left tackle might be the most important position on the offensive line, and the Jets could be looking to find an upgrade if they decide to not re-sign Kelvin Beachum.

It isn’t saying much to point out Beachum ranked highest among Jets linemen in 2019. Joe Douglas would be foolish not to at least explore the free agent market for a new left tackle if he thinks he can find someone who can better protect Sam Darnold.

The left tackle market is a little wonky. It basically consists of one young, elite talent, two aging veterans way past their primes and a couple of unproven or inexperienced players. Douglas should navigate this pool carefully before pulling the trigger on a high-priced tackle, especially considering how many other positions of need he has to bolster.

Here are the five best left tackles the Jets should target.

Anthony Castonzo 

If protecting Sam Darnold is what Joe Douglas is looking for from a new starting left tackle, Colts free agent Anthony Castonzo is the best on the market. He’s the eighth-ranked left tackle in pass-protection with an 84.4 Pro Football Focus grade, and the fifth-ranked in dropback passing scenarios. Castonzo is also incredibly consistent, posting overall grades between 76.9 and 83.4 since 2012.

Castonzo is still relatively young – he’ll turn 32 in August – and has the ideal size at 6-foot-7 and 307 pounds for a premier tackle. He’d fortify the offensive line no matter who else Douglas brings in, but it would come at a premium. Castonzo will likely require somewhere between $14.5-$16 million per year, much like Titans tackle Taylor Lewan got in 2018 with a five-year, $80 million deal.