The Cowboys are hosting LaAdrian Waddle on a visit, according to Ian Rapoport of NFL.com (on Twitter). He joins fellow Patriots free agent tackle Cameron Fleming who is also meeting with Dallas. 
The Pats are hoping to retain one or both tackles, particularly after losing Nate Solder in free agency to the Giants. The Cowboys, meanwhile, are looking to reinforce their already powerful offensive line.
Dallas seems pretty set with Tyron Smith and La’el Collins at the tackle spots, but Waddle or Fleming could be slotted in at right tackle, allowing La’el Collins to shift back to left guard. That would push former third-round pick Chaz Green back to a reserve role and leave Dallas with a starting five of Smith, Collins, Travis Frederick, Zack Martin, and Waddle or Fleming. It’d be hard for any other team to top that.
If the Cowboys are intent on keeping Collins at tackle, it’d probably be tough to lure Fleming in as a backup, but Waddle could be receptive to a reserve role. In 2017, Fleming played 543 total snaps and graded as the league’s No. 24 offensive tackle, per Pro Football Focus. Waddle, meanwhile, played 380 snaps, and was PFF’s No. 64 offensive tackle.
Whomever Is able to play LT is the best option. I don’t know is we can rely on Tyron Smith’s health anymore. Sign one of them, and then maybe draft a tackle in the middle rounds. Chaz Is at best a backup guard.
Chaz is looking like a training camp cut at this point
LaAdrian is kind of an awkward name phonetically.