Niemann has been terrific of late for the Rays, as he has gone 5-0 over his last eight starts and has pitched to a 2.26 earned run average in that time to lower his ERA over two runs to 3.58.
"It's really just been throwing strikes with the fastball, and I've been able to throw the breaking ball for strikes also," Niemann said. "The execution has been a lot better overall."
Niemann pitched into the ninth inning to secure a win over Oakland on Friday, as he allowed four runs and seven hits in 8 2/3 frames to improve to 6-4 on the year. He also struck out eight and walked a batter in the win.
His recent success could continue today given the fact that Niemann is a perfect 3-0 lifetime against the Royals with a 1.15 ERA in five games, four starts.
Tampa stunned Kansas City on Wednesday by scoring five times in the ninth inning to steal an 8-7 win. Sam Fuld drove in the tying run with a triple and scored the winning run on Johnny Giavotella's throwing error to help the Rays win for the ninth time in their last 13 games.
"To be able to come back like that is an outstanding testament to this group of people," Rays manager Joe Maddon said.
Jake McGee (1-1) picked up his first win in the majors despite giving up two runs in the ninth.
A win today would five the Rays their first four-game sweep over KC since turning the trick from July 28-31, 2005.
Melky Cabrera hit a three-run homer and drove in five for the Royals, who have lost five of six.
Joakim Soria (5-5) was charged with three runs -- two earned -- on three hits to take the loss. It was his seventh blown save of the season, tying him for the major league lead.
Today, the Royals turn to left-handed rookie Danny Duffy, who is 3-5 with a 5.08 ERA. Duffy was charged with the loss on Saturday against Detroit, as he allowed three runs and five hits in five innings.
"I didn't have very good command," said Duffy, who has pitched to a 7.04 ERA over his last three starts. "It is what it is. I just didn't do my job. Didn't locate very well. And it's frustrating. Really frustrating."
Duffy has never faced the Rays.
Kansas City took two of three from the Rays earlier in the year. However, the Royals have won just four times in their last 20 visits to the Trop and have managed two runs or less in 14 of those contests.