The 22-year-old will try to begin changing that Thursday night against the Pittsburgh Pirates and help the visiting Braves get back on track a day after their 10-game winning streak was snapped.
Atlanta's pitchers easily boasted the best ERA in the majors (1.83) during the club's 12-1 start and lowered that to 1.77 on Wednesday, but didn't get any offensive help in a 1-0 loss to Kansas City.
That kept the Braves (12-2) from their first 13-1 start since 1994.
"We feel like we can win every one of them," said second baseman Dan Uggla, who was called out on strikes to end Wednesday's game. "We'll just have to come back tomorrow and start another streak."
Teheran (0-0, 7.36 ERA) will look to help Atlanta bounce back with a better start to this outing. The right-hander gave up four runs in the first two innings Friday in Washington before settling down to allow two baserunners over four additional scoreless frames in a 6-4 win.
"For a young kid, the wheels definitely could have come off, and then next thing you know, he gives up five or six runs, and then we're into the bullpen early in the game," catcher Gerald Laird told the team's website. "He bounced back and showed me something. He battled."
In his first start against Pittsburgh, Teheran will face a club that's won six of eight after a 1-5 start. After giving up 10 runs to St. Louis on Monday, the Pirates (7-7) recorded their second shutout of the season, yielding one hit and no walks in a 5-0 win Wednesday.
Jeff Locke (1-1, 4.09) will try to build on that with another strong outing against Atlanta. The left-hander gave up one run and two hits over six innings in a 2-1 victory at PNC Park on Oct. 1.
After losing his season debut April 7 against the Dodgers, Locke worked around four walks to yield just a solo homer and three other hits in a 3-1 win over Cincinnati on Saturday.
"He competed and somehow he was able to get the big outs when he needed them," manager Clint Hurdle said.
Justin Upton, who has a major league-best eight homers, is 3 for 26 in his last eight games against Pittsburgh. He has never faced Locke.
Pirates left fielder Starling Marte, the owner of a career-high 10-game hit streak, went 5 for 13 in his only series against the Braves in October. He's 8 for 13 when leading off a game this season and tripled in his first at-bat in Wednesday's victory.
The Pirates edged Atlanta in last season's series (4-3) for the first time since 2009, winning two of three at PNC.