(Photo credit: Rafael Suanes-Imagn Images)

After replacing Washington Nationals manager Dave Martinez on an interim basis, Miguel Cairo will try to guide this re-tooling team onto a positive track.

'We have a lot of interesting, exciting young pieces to build on,' interim general manager Mike DeBartolo said Tuesday. 'We have a lot more we need to build on. Simply stepping up our game is not enough. We need real change.'

That challenge will continue Wednesday night in St. Louis when the Nationals face the Cardinals in the middle game of a three-game series. The Nationals lost 4-2 Tuesday night to extend their losing streak to four games.

What is Cairo's message to the team?

'My friend Dave Martinez asked me to continue his legacy, to continue doing this job for what we start from the beginning,' Cairo said. 'To me, that was the most important.'

The Nationals on Wednesday will start left-hander MacKenzie Gore (3-8, 3.11 ERA), who has allowed just three runs on eight hits over 11 1/3 innings in his last two starts.

Gore is 0-2 with an 8.57 ERA in four career starts against the Cardinals. He suffered a 6-1 loss to them on May 11 after allowing four runs on five hits -- including Willson Contreras and Lars Nootbaar homers -- in 6 2/3 innings.

The Nationals placed catcher Keibert Ruiz on the seven-day concussion injured list and recalled catcher Drew Millas from Triple-A Rochester on Tuesday. Washington also signed reliever Luis Garcia and optioned Eduardo Sanchez to Rochester.

After enjoying an off-day Monday, the Cardinals pushed starting pitcher Andre Pallante (5-4, 4.10 ERA) back to Wednesday so that staff ace Sonny Gray could start Tuesday's game on regular rest and get two starts before the All-Star break.

Pallante, a right-hander, has allowed just two runs in 18 innings over his last three starts while solidifying his place in the long-term rotation.

'His last three have been good, and that's why you have to be somewhat patient with these guys because there is development taking place and this is the type of outing you want to see,' Cardinals manager Oliver Marmol said.

'I still think there's room for me to go,' Pallante said after throwing seven scoreless innings in a 1-0 loss to the Pittsburgh Pirates on July 1. 'I threw a sweeper for the first time in the game today. I threw one of those in there, just trying to get some work, just to see if I can get a better chase pitch to righties. Threw it to the backstop, but you know, gotta throw one first before I can get a little more comfortable and start working on it in the game.'

Pallante is 2-1 with a 5.40 ERA in six career appearances against the Nationals, including two starts. He earned a 4-2 victory at Washington on May 10, holding the Nationals to two runs on five hits in 7 1/3 innings. He struck out seven and walked one.

Cardinals third baseman Nolan Arenado remained sidelined by a shoulder impingement Tuesday but hopes to return Wednesday to add another right-handed bat against Gore.

'Try to give it one more day, that way I'm in there (Wednesday) playing,' Arenado said Tuesday.

--Field Level Media