Of the two, Tavarez has experience as a closer. He saved 11 games for the Pirates in 2003. He said he doesn't have a problem pitching in the late innings.
"I feel fine with the role. I never think about when I'm coming into the game. I'm always ready," Tavarez said.
Acta made the change because of what happened Monday night at Citizens Bank Park. In the bottom of the eighth, the Nats had an 11-7 lead over the Philies, but Mock and Hanrahan couldn't get the job done.
With Mock on the mound, Shane Victorino hit a sacrifice fly to bring in Pedro Feliz and make it 11-8. After Chase Utley singled in Jimmy Rollins, Hanrahan entered the game and couldn't find the strike zone, walking both Ryan Howard and Jayson Werth on 10 pitches.
Raul Ibanez then came to the plate. Hanrahan felt he had no choice but to throw a fastball, and he paid the price, as Ibanez hit a grand slam. It was Hanrahan's third blown save of the season.
"I hope I don't wear out this word, but, again, it was deflating," Acta said after the game. "Our offense just battled all day and scored enough runs. We played so hard for eight innings to score enough runs. You lose the game in one inning, it's just tough for the whole team."
Acta believes Hanrahan has put too much pressure on himself because the team was off to a slow start.
"He wasn't as positive and aggressive as he should be in that type of situation," Acta said. "When you have that type of job, you have to believe in yourself. You have to attack hitters, and get it done. Don't have any negative thoughts in your head. We think Joel has the stuff to do it. He has to earn his way back over there."
Hanrahan had a feeling that he would lose his job based on the season he was having. He had an 8.64 ERA entering Tuesday's action. Hanrahan also didn't deny that he put too much pressure on himself.
"You can't be running the same guys out there in the ninth with the game on the line and a chance to win the game," he said. "If the same guys are not getting the job done, you have to mix it up. I just have to get back to where I have to be."
If Tavarez and Wells don't pan out, what can the Nationals do to make the bullpen better? It turns out that Acta's and general manager Mike Rizzo's hands are tied.
There is no one in the Minor Leagues that could help them right now. Right-hander Jesus Colome is not eligible to go to the Majors until May 15.
The Nationals could try to acquire relievers via trade. The problem is, opposing teams are not interested in players such as first baseman Nick Johnson and Austin Kearns due to their high salaries.