Middlesbrough drew 0-0 with Ipswich Town at the weekend, leaving their automatic promotion hopes hanging by a thread.
The Teeside club currently sit second in the Championship table, only losing out on top spot because of an inferior goal difference to league leaders Burnley.
Downing spoke to mfc.co.uk about his side's upcoming trip to St Andrew's, saying, “We had a couple of days rest after the Ipswich game to get out of the building and clear our heads.
"We trained on Tuesday and it was good. The lads are all buzzing for it this Friday. It’s all still in our hands and that’s what we’ve been speaking about – we just need to keep winning the games."
A win for Boro would pile the pressure on Burnley and Brighton & Hove Albion, who do not play until the following Monday.
The 31-year-old former West Ham man has played a key role in the North East club's impressive season. He has taken part in all Boro's Championship games bar one, chipping in with three goals and five assists, and his experience will be invaluable as Middlesbrough attempt to make their way back into England's top tier.
He finished off by praising the Boro support, after it was announced that 5,000 fans will be making the trip to the Midlands on Friday night.
“The fans were really good at the weekend," Downing said. "We had a lot of chances in the game, then it gets a bit edgy and they’re maybe liable to nick a goal. But we kept going and creating and the fans got behind us. That’s what you need because these can be nervy times for the players. The fans have always been good. There are a lot of Boro fans going to Birmingham, including family and friends and we need a good result for everyone."
Following on from the Birmingham game, Middlesbrough are set to host Brighton on the last day of the season in a match that has the potential to be an automatic promotion decider.