The UFC on Wednesday announced the addition of a lightweight bout between Thiago Tavares and Nik Lentz to the un-aired preliminary portion of its UFC Fight Night 20 event.

The UFC also confirmed a previously reported welterweight bout between TUF 7 winner Amir Sadollah and Brad Blackburn for the main card of UFC Fight Night 20.

Tavares replaces Lentz's second opponent for the event, Jeremy Stephens, who withdrew from the fight due to an injury suffered in training.

Lentz seems like he can't keep an opponent for UFN 20, as match ups with his previous two opponents have been scratched. He was originally expected to meet Efrain Escudero, however, Escudero was pulled from the bout in favor of a co-headlining fight against Evan Dunham on the same card.

Tavares (14-3) hasn't fought since defeating Manny Gamburyan at UFC 94 in January. He was set to fight Melvin Guillard at TUF 9 finale in June, however, was forced off of that bout with an elbow injury. Tavares then was scratched from a match up against Jim Miller at UFC 103 in September because of a knee injury.

The win at UFC 94 snapped a two-fight losing streak for Tavares, previously losing back-to-back fights against Matt Wiman and Kurt Pellegrino. He is 4-3 in seven bouts with the UFC, scoring other Octagon wins over Michihiro Omigawa, Jason Black and Naoyuki Kotani. The six-year veteran of the sport has finished an outstanding 10 of his 14 career wins by submission.

Lentz (17-3-1) is on a nine-fight unbeaten streak, which includes a draw with WEC veteran Kyle Jensen, as well as wins over Travis Perzynski, Dan Loman and UFC veteran Drew Fickett. The Minnesota Martial Arts Academy product most recently defeated fellow UFC newcomer Rafaello Oliveira in his UFC debut in September at UFC 103.

UFC Fight Night 20 takes place on Jan. 11 at the Patriot Center in Fairfax, Virginia and the main card will be televised live on Spike TV. Headlining the event is a crucial lightweight tilt between TUF 5 rivals Gray Maynard and Nate Diaz.