Remi Garde led Aston Villa to a 0-0 draw against Manchester City during his first match in charge.
Sanchez was handed a place in Villa’s starting line-up by Garde, and he put in an excellent performance against Manchester City.
The Colombian international was combative and creative against City, as his side picked up a highly credible 0-0 draw.
And Keown said: “I thought Sanchez looked a totally different player in that midfield, and [Jordan] Amavi showed good signs.
“But in the final third Remi Garde will have to work on them. He needs to create that imagination in the final third.”
Villa were much improved against City, and the work that Garde had done with them on the training ground was clear to see.
The Claret and Blues looked organised and robust throughout the contest, and Jermaine Jenas was also very impressed by their performance.
“I have never seen such a big difference, really, in one game. Remi Garde is showing how he is going to be playing,” the former Tottenham Hotspur midfielder said.
Villa’s draw at City has given them a precious point, but they are still in the thick of a relegation battle.
The Villains are currently five points away from safety, and they will need to start picking up victories quickly if they are to get out of trouble.