A veteran quarterback joins the Dallas Cowboys following the injury to Tony Romo as Matt Cassel was acquired to be a backup via a trade deal from the Buffalo Bills.

Included in the deal, the Cowboys also received the Bills' 2017 seventh-round pick in exchange for a fifth-round pick in the same year. 

The Cowboys lost Romo to a collarbone injury in their second straight win of the 2015 season against the Philadelphia Eagles last Sunday. 

Romo is expected to be out for eight weeks, although tests revealed that a surgery is not needed. 

The 35-year-old quarterback was placed by Dallas on the injured reserve/designated to return list last Tuesday and will be available to return on Nov. 22 when they play against the Miami Dolphins. 

In Romo's absence, quarterback Brandon Weeden will be replacing him as the Cowboys starter and the latest trade move makes Cassel the backup. 

Before getting the trade for Cassel done, the Cowboys held workouts in their search for a number two quarterback.

Weeden replaced Romo in their match against Philadelphia and that game was his first this season. 

The 31-year-old footballer completed all seven of his passes for 73 yards and one touchdown in their win over the Eagles. 

Meanwhile, Cassel was given the backup quarterback role with the Bills behind starter Tyrod Taylor but is yet to play a snap this season. 

During the Bills' training camp and preseason, Cassel competed for the starting quarterback job with Taylor and EJ Manuel. 

Cassel is a proven veteran and is in his 11th season in the NFL. 

Before joining the Bills and getting traded to the Cowboys, the 33-year-old quarterback played for the New England Patriots, Kansas City Chiefs, and the Minnesota Vikings. 

The addition of Cassel shows Dallas' need for a veteran in case Weeden, who is in his fourth season, will be unable to lead the Cowboys' offense.