Rowe, Team Sky's road captain, broke a rib in a crash on the opening stage but rode on to support team leader Froome.
The 27-year-old finished as lanterne rouge, an honour for the rider in last place on general classification, noting the sacrifice of their own ambitions to help their team's bid for yellow.
"That's incredible," Brailsford said of Rowe's effort after breaking his rib.
"They're so robust, these guys, and he went down really hard.
"He caught his rib on the pavement as he went into it and probably did more damage than we originally thought.
"He was in a lot of pain but he pulled through and he's so good as a road captain - he communicates so well.
"We would have been in big trouble without him actually so it was great that he pulled through."
Froome's winning time of 86 hours, 20 minutes and 55 seconds saw him finish 54 seconds ahead of Rigoberto Uran in second place.
Rowe ended the race four hours, 35 minutes and 52 seconds behind Froome as he toiled in order to help the Team Sky leader claim his third successive title.
The Welshman finished 167th in the general classification, more than three minutes adrift of second-from-bottom Tom Leezer.
But the lanterne rouge is something of a badge of honour for Tour cyclists, with Rowe spending much of the 2017 race chasing down breakaways at the front, then bringing up the rear of the peloton having spent all his energy in Froome's cause.
BeSpoke: Download the Radio 5 live podcast
Find out how to get into cycling with our special guide.
Team Sky boss Dave Brailsford praised Luke Rowe after he helped Chris Froome win his fourth Tour de France title.