Blanco came on in the 60th minute and sparked the Fire with a goal and an assist in Chicago's 2-0 victory over the San Jose Earthquakes on Saturday.
"I'm happy that I could help my team with a goal," Blanco said. "Things hadn't been going well for the team at home so it was important to win this game in front of our fans.
"The team was very concentrated. We knew we needed to win this game and so the team was focused and we got the win."
This is the second player of the week award for the 36-year-old Mexican international.
The MLS Player of the Week is selected each week by a panel of journalists from the North American Soccer Reporters. The group consists of members of online, print, television and radio media.