Tensions could reach a boiling point when the Mets host the Phillies on Wednesday night at Citi Field.

Frustrations have been mounting for the Phils, who have lost five of their past six games, and the club clearly did not appreciate it when Mets right-hander Jacob Rhame threw multiple fastballs near the head of Rhys Hoskins in the ninth inning Tuesday.

“I’ll just speak for me and say I’m still fairly upset about how last night’s game ended," Phillies manager Gabe Kapler said prior to Wednesday's series finale. “I don’t think I need to rehash the details about the end of the game last night. I’ve said quite a bit about it already.”

Despite emotions running high, umpires are not expected to issue warnings prior to Wednesday's first pitch, according to Andy Martino of SNY. That said, umpires still have the authority to eject any pitcher they believe is intentionally throwing at a batter.

That's perfectly fine with Mets skipper Mickey Callaway, who insists his team will be focused solely on trying to finish off a sweep of its division rival.

"I get why they were concerned, but we're not concerned at all," Callaway said. "We're going to go out there and play the game that we have to play to win. That's what we're here for. We're here to win. And we can't concern ourselves with that. If something happens, we'll deal with it appropriately, and then keep on trying to win. That's why we're here."

So how exactly would his club "deal with" any potential issues that may arise?

"They know what to do," Callaway said. "They're going to have each other's backs. We're a team. That's a team full of brothers in there that's going to do anything they can to protect each other. So we'll deal with whatever we have to deal with appropriately."

Kapler was the first one out of the dugout on Tuesday night after the first pitch to Hoskins sailed behind the slugger. Hoskins took a few steps toward the mound and up the third-base line while staring out at the mound, and both dugouts began to empty, though the situation didn’t escalate any further.

When Rhame threw another pitch up and in for ball four, Hoskins angrily tossed his bat toward the Phils’ dugout, momentarily stared down Rhame and had some words with catcher Travis d’Arnaud before taking his base.

"When you accidentally sail one, it's probably pretty scary," Rhame said. "I'd get [angry], too."

Hoskins was not buying the Mets’ explanation that Rhame was trying to pound him inside.

"He didn't miss up and in the rest of the inning, so I'll let you decide," Hoskins said. "I would assume teams are pitching me in because that's where they think they can get me out, and that's fine. That's part of the game. Again, I think most guys are capable of pitching inside and not missing that bad."

Prior to the close calls in the ninth inning Tuesday, both Jeff McNeil and Pete Alonso were hit by pitches from Phillies arms over the first two games of the series, but Phillies outfielder Bryce Harper didn’t think that was any excuse to throw at someone’s head.

"I don't get it," Harper said. "I understand that two of their guys got hit yesterday. But, I mean, if it's baseball and you're going to drill somebody, at least hit him in the [butt]. Not in the head. You throw 98, it's scary now. You could kill somebody. Lose your eyesight. That's bigger than the game.”

Harper caused a stir in his own clubhouse Monday night, as he was ejected for arguing balls and strikes with home-plate umpire Mark Carlson, prompting some critical comments from starter Jake Arrieta.

“We need him in right field,” Arrieta said. “I don’t care how bad [the umpire] is. I need him in right field, I need him at the plate and he wasn’t there. So that hurts.

“I’m out there, trying to make pitches, he misses some calls. So what? Like, we need him out there. We were flat from start to finish. Two-hour delay, it doesn’t matter. We have to be ready to play. We weren’t and it showed.”

The rising animosity is reminiscent of an August 1990 series between the two clubs, who engaged in a bench-clearing brawl that was sparked by Dwight Gooden charging the mound after being hit by a Pat Combs pitch.

Problems initially arose earlier in that series, with starters David Cone and Don Carman exchanging questionable pitches in the series opener, and Gooden had hit two Phillies batters before getting plunked himself.

The National League East foes had one of the game's most heated rivalries in the mid-to-late 2000s, with the Mets taking the division title ahead of the second-place Phillies in 2006, and the Phils barely edging the Mets in 2007 and 2008 as they started a run of five straight NL East crowns.

Though the rivalry has remained, the two clubs haven't been in a postseason race against one another since 2008. It appears that is going to change this season, and the temperature of the rivalry appears to be rising as a result.