Stoke looked set to secure all three points when Victor Moses and Mame Biram Diouf put them two goals up in the Premier League encounter at the Britannia Stadium back in November, but Sam Allardyce's side refused to be beaten.
Downing crossed for Valencia to pull a goal back and the England man salvaged a point with a goal of his own when the Ecuador international turned provider 17 minutes from time.
West Ham are ninth in the table after a 2-1 defeat at bottom side Leicester City last weekend left them with just one win in nine league games and the London club are only ahead of Stoke on goal difference.
Former Liverpool player Downing is determined to get back on track this weekend and has welcomed the return of striker Valencia after he recovered from a toe injury.
"We're on the same number of points, so it's a massive game," Downing told the club's official website.
"It was a difficult one when we played there and we got a draw out of it, but we're at home now and I think Enner's back for the weekend. Diafra [Sakho] is there too so we can have a right good go at them and get the goalscorers back in the team.
"It was a good game for me when we played earlier in the season, scoring one and setting Enner up too. It was a game of two halves – in the first half we were poor and didn't get going, but in the second half we were really good.
"We need to get back to winning ways on Saturday because we don't want the season to tail off – we want to finish as strongly as we can."
West Ham have scored only two goals in their last four matches, so Downing sees Valencia's comeback as a timely boost with Andy Carroll on the sidelines due to a knee injury.
He added: "He's a goal threat. He's got pace, he's powerful and he's a threat to the other team. I thought he played ever so well, especially in the second half, at Stoke. Their defenders will know they're in for a game.
"Him and Sakho have been a good partnership when Andy's been out so it'll be interesting what team the manager picks but I'm sure he’ll be in his thoughts and it's nice to have him back.
"I'm sure the manager is happy to have those options. He has Carlton as well who will be itching to play. He did well when he came on against Sunderland at home."
Stoke head to the capital for the second successive weekend and Hughes' men will be out to end a run of three consecutive defeats.
Charlie Adam scored one of the great Premier League goals from 65 yards at Chelsea last Saturday, but the midfielder's wonder-strike came in a 2-1 loss.
Peter Odemwingie and Bojan Krkic (both knee) are Stoke's only absentees.
