"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."
Welker took a hard hit to the head from Houston Texans safety D.J. Swearinger after making a catch over the middle in the second quarter of the Denver Broncos' 18-17 loss.
With smaller wide receivers Julian Edelman and Danny Amendola, who have a similar playing style to Welker, Brady knows head injuries are of a concern.
"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."
Last season, Amendola sustained a concussion on an end-around against the New Orleans Saints on a play in which he drew ire because he may have been able to protect himself. Now, Brady is proactive about trying to avoid those types of injuries with Edelman and Amendola.
"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."
Brady understands that football is a bang-bang sport, but he would rather have his teammates healthy throughout the course of a game or season over having them make one big play and suffering an injury.
"Sometimes you don't have that opportunity [to protect yourself], and in football you just have to go for it," Brady said. "When you have an opportunity to take care of yourself and play the next play, those are the decisions you have to make."