Tom Brady and Wes Welker are no longer teammates, but that doesn't make it any easier for the New England Patriots quarterback to see one of his former targets dealing with another concussion.

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Brady, who called Welker one of his "best friends," felt remorse to see the Denver Broncos wide receiver dealing with his third head injury in less than a year.

"It's tough to see that happen and to a guy like Wes, who is one of my best friends," Brady said in his weekly interview on Boston sports radio station WEEI. "He is as tough as they come, so you hate to see him go through those things, but to see it happen for the third time in a little less than a year is a tough thing. It's a tough thing for any player to deal with."

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Welker was injured in the second quarter of their 18-17 preseason Week 3 loss to the Houston Texans after he caught a pass over the middle and was hit by Houston safety D.J. Swearinger.

Having seen his current teammate and wide receiver Danny Amendola go down with a concussion last season, Brady knows there is a growing concern about head injuries in the NFL.

"It's a tough thing to see when you see guys get injured, certainly head injuries, which has been a big topic of conversation over the last few years," Brady said. "The NFL and the players' association are trying to do the best they can to eliminate those types of injuries, but they are going to come up because it is a contact sport."

Brady acknowledged that a lot of head hits come very quickly and are unavoidable at times.

"It's literally split-second decisions, split-second timing on certain plays," Brady said. "And I just think the attitude of a lot of players is just to do whatever it takes to help the team. I try to talk to the receivers a lot about making good decisions."

In 13 games last season, Welker had 73 receptions for 778 yards with 10 touchdowns as Denver went on to win the AFC title before falling to the Seattle Seahawks in the Super Bowl.

Brady and New England notched their fifth straight AFC East division title last season en route to losing to Welker and the Broncos in the AFC Championship Game. In 2013, Brady went 380-for-628 (60.5%) for 4,343 yards with 25 touchdowns and 11 interceptions.

The Patriots and Broncos cross paths again in Week 9 on Nov. 2, but it remains to be seen if Welker will be back.

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