There is a comforting monotony to baseball, a day in, day out meter you can put a baby to sleep to.

Routine is everything, especially for players.

With the Brewers, the routine isn't necessarily orthodox.

It includes tweets from John Axford, visits by Aaron Rodgers, and losing remote control planes in the roof of Miller Park.

It's a good time, but it's routine.

That has been broken up a bit this week, at least for one player.

On Tuesday, between the usual goings on of the relievers, was an empty chair.

The now famous stickered candy bag beside it looked lonely

The seat remained vacant for longer than usual considering the bullpen was mostly together.

Marco Estrada eventually walked in, spun it around and flopped into it with a breath. He destroyed a bottle of water before wiping down his face and neck.

The eight or so sprints the relievers do before shagging flies in batting practice won't cut it anymore for Estrada, who has been called upon for the ultimate relief role – that of an injured starting pitcher.

Last year, he filled in for Zack Greinke at the start of the season. The former Cy Young winner was on the mend from an off-season basketball injury, so Estrada knew his time in the rotation was limited.

This year, Chris Narveson is done for the year with a torn rotator cuff.

He has to prepare now as if this relief appearance will become more permanent.

"A 45-minute run here, 40-minute run there," he said. "It's just a longer time. It doesn't mean it's harder or anything, just a longer period of time. Just stamina – that's all I want to build up right now."

Fortunately for Estrada, he's been preparing for this since the Brewers convened in Arizona for spring training.

At that time, there was uncertainty surrounding the health of Shaun Marcum, so the 28-year-old Estrada was built up as a starter would have been.

Despite not throwing 90 pitches since the team broke camp, the base work set him up for an easier transition to his start on Saturday against Colorado in which he struck out nine over five innings in a Brewers win.

"That kind of helped because they were building me up just in case," he said. "I don't know if they would've done the same thing if everybody was healthy. I thought it helped. Even then, my last outing, I got tired still.

"But I guess it had been three weeks since the last time I threw 90 pitches. But it helped. There was no way I could have gone 78 pitches and five innings without throwing 90 pitches back in spring training."

His goal his next start is to go at least seven innings, hence the increased running and lifting regimen.

As a reliever, you can be called upon on any day, so they have to stabilize their workouts – nothing overly heavy, nothing overly soft. Starting is different, with four days off in between appearances.

So, Estrada has hit the ground, building up his leg strength.

It's really the only change in routine for him, as he won't participate in any extra bullpen sessions.

"It's truly not that big of a change, to be honest with you," he said with a shrug. "At least I don't feel it is. Other than my conditioning, everything seems about right and it all stays the same."

Manager Ron Roenicke said Estrada is penciled in as the team's fifth starter for now, knowing he went 3-2 with a 3.70 ERA in seven starts last season.

"I really like Marco," Roenicke said. "This guy has pitched good for us so I have no problem with him being in the rotation."

For his part, Estrada will continue to work, to run, and be ready when called upon – whether it's to take the ball every fifth day or contribute new mementos to the candy bag as a member of the bullpen.

"I just want to go out and do my job," he said. "If people notice it, great, if they don't, I don't care. As long as I'm getting the job done, that's all that really matters."