Seo said he hesitated at first, thinking the ball was foul.
Such a mental lapse is not conducive to winning baseball, according to Maddon, who said of the play and its aftermath: "The baseball gods do punish you for not doing the right things."
Seo's punishment arrived very shortly.
Rays catcher Josh Paul threw out Matthews trying to steal second. Seo then walked Orlando Cabrera, and Vladimir Guerrero followed with his sixth home run of the season.
The Angels scored nine runs in the final four innings of Wednesday night's 9-1 win over the Rays, and they continued to pound the baseball against Seo with five runs in the first. Seo managed to get one out in the second before he left with a line that showed six runs on seven hits in 1 1/3 innings.
"He wasn't sharp today, and they just kept piling it on," Maddon said. "When you get that kind of starting performance, it makes everything look bad. And we played poorly today."
Seo explained that he lost his focus and has struggled to keep the ball down. He entered Thursday's start having won just twice in 20 starts since coming over from the Dodgers in a midseason trade last summer. He has now allowed 52 baserunners in his last 23 2/3 innings. Despite Seo's numbers, Maddon plans to stick with him.
"I have a lot of faith in this young man," Maddon said. "We just have to find out what's going on and see if we can elevate him a little bit. I see him as being much more consistent than he's shown to this point."
Meanwhile, Pena's two-run homer in the fourth was all the Rays could mount against Angels right-hander Bartolo Colon, who was making his second start of the season after coming back from a torn right rotator cuff. Colon allowed just four hits while striking out 11 before leaving after seven innings with the Angels safely ahead, 11-2. Rays hitters finished with 14 strikeouts, a total they last reached on July 20 against the Twins.
"We strike out too much," Maddon said. "We talked a lot about that in Spring Training. You look at our numbers, there's a lot of good stuff going on, we're really happy with a lot of things. But we have to cut down on that. But then you also have to tip your hat to Bart."
Maddon, who saw Colon up close when both were with the Angels, said Colon had his "A" stuff.
"The movement, the location, the breaking ball was a lot sharper than the last time I'd seen it prior to him getting hurt. He was on," Maddon said. "We saw two good pitchers the past two days. And they have a wonderful staff."
After sweeping a two-game home series against the Yankees, the Rays were swept in a series for the first time this season. Maddon said the contrast in the team's performance was bothersome.
"We played so well, and that's part of what I want to eradicate here," Maddon said. "When we start going, well we kind of let up. And we can't do that. That's ridiculous. We haven't done anything yet that allows us or permits us to think that you win two hard-fought games and then all of a sudden you're pretty good.
"We've got to keep pounding at the door regardless of what happened the day before. I do believe the travel may have played a little bit into this whole thing. The scheduling was not the finest. But you still have to deal with and fight through those moments. That's part of the game. It's on the schedule. We have to take care of it a lot better in the future. That was just a bad day. It just started poorly and ended poorly. It was a bad day. There's no way to sugarcoat that one. It was a bad day."