Tackle-bust Flowers will be free in 2019

The day after Ereck Flowers hired Drew Rosenhaus, it became even clearer Wednesday how much the disappointing Giants offensive lineman will need the super agent in the future — because the team opted not to pick up Flowers’ fifth-year option, making him a free agent after next season, a source confirmed.

The ninth pick in the 2015 draft, Flowers would have been owed $12.52 million in 2019, making this move an easy one for the Giants. His salary cap hit is $4.57 million this season. The Giants tried to trade Flowers before last week’s NFL draft, but received few worthwhile offers, The Post reported.

Flowers hasn’t exactly ingratiated himself to new Giants coach Pat Shurmur and general manager Dave Gettleman by skipping voluntary spring workouts. He can be fined or disciplined for not showing up for minicamp in mid-June.

The 24-year-old Flowers has started 47 of a possible 49 games at left tackle in his three seasons, and has mostly struggled as the poster boy for the weak unit. His problems protecting quarterback Eli Manning’s blind side led the Giants to sign free-agent left tackle Nate Solder to a four-year, $62 million deal in March.

With Solder now anchoring the group, Flowers will move over to right tackle, where he will compete for a starting spot.

Also on Wednesday, the Giants added experience to their quarterback room by signing veteran Alex Tanney. The 30-year-old, who spent last year on injured reserve with the Titans after breaking his left foot, has been in the league since 2012.

The Giants also signed defensive tackle A.J. Francis, who was cut by the Redskins on Monday, and claimed veteran cornerback C.J. Goodwin off waivers from the Cardinals.