Toronto are winless in four matches and host a team also competing for a play-off spot in the Eastern Conference.
Vanney said there were aspects of his side's performance which needed to improve, particularly with their work in transition.
"We had to work through some things in the first half," he said.
"We weren't able to really move our attack into the opposition's half and from a possession standpoint, they sat back and waited for us, and our spacing and positioning wasn't such that we really made them make some decisions.
"One of the things we talked about today was trying to be a little more forward-thinking with that initial pass out of transition.
"In the first half, we weren't winning balls where we were looking to win balls. We were getting a little bit stretched out."
The in-form Los Angeles Galaxy, still challenging for the Supporters' Shield, host the struggling Colorado Rapids.
The New York Red Bulls host Sporting Kansas City needing a win as they chase a play-off spot.
The Houston Dynamo and Montreal Impact, bottom two in the conference, also do battle.
Eastern Conference leaders DC United will fancy their chances when they travel to the Vancouver Whitecaps.
Western Conference contenders Dallas and Real Salt Lake clash, while struggling Chivas USA travel to the Columbus Crew.
The San Jose Earthquakes need a win when they visit the Portland Timbers and New England are aiming for their fourth straight win when they host the Chicago Fire.