MESA, Ariz. -- Javier Assad maintained a stoic expression, but a smile started to form in the corner of his mouth as he listened to the question. The Cubs’ rookie pitcher pondered his reply.

The question posed to Assad was this: If he could go back two years and tell himself that -- by this spring -- he would be capable of throwing a 97 mph fastball beyond the bat of a slugger like Pete Alonso, how would he react?

"I don't know what I would say," Assad said via a translator. "But I know that I'd be really happy. And I have been really happy."

In Friday's 5-3 Cactus League victory over the Rangers, Assad made his first appearance for the Cubs after his eye-opening stint with Team Mexico in the World Baseball Classic. The righty entered in relief of Opening Day starter Marcus Stroman and struck out the first batter he faced in his return.

That is the kind of spring it has been for the 25-year-old Assad, who continues to make his case for inclusion on the Opening Day roster in some capacity. He remains a candidate for the lone rotation vacancy, but Assad is also a contender for a multi-inning relief role.

"It's been super impressive," said new Cubs catcher Tucker Barnhart, who caught Assad's outing against the Dodgers on Feb. 26. "There's things that you see in Spring Training, even early on, that you can tell are going to carry on throughout the spring and then going to carry on through the season. And his fastball had life at the top of the zone."

Command of a wide array of pitches has always been Assad's strength, but the right-hander has made great strides via a velocity program over the past two offseasons. During his time with Team Mexico, he was sitting in the 94-96 mph range with his fastballs, and he hit 97 mph on a strikeout of Alonso while facing Team USA.

Fellow rookie Hayden Wesneski -- also a contender for the fifth spot in the rotation -- touched 97 mph on the Sloan Park radar gun during his most recent spring outing Thursday. He laughed when asked if he was trying to keep pace with Assad.

"I'm trying to be like Javy," Wesneski quipped. "That dude, he's incredible. I'm telling you right now -- he gets outs. He knows how to pitch. He competes, and he's consistent."

Overall against Texas, Assad worked three innings, striking out four, walking one and staying in the 93-95 mph range with his heater. Between Cactus League play and the Classic, the right-hander has turned in a 1.42 ERA this spring with 12 strikeouts and three walks in 12 2/3 innings.

"I'm here to help the team the best way I can," Assad said. "Whether that's starting or relieving, I'll give everything I have."

Cubs manager David Ross said he saw how "fearless" Assad was down the stretch last season, when the pitcher posted a 3.11 ERA in a nine-game audition. One example: Assad's first career strikeout came against Albert Pujols during the legend's march to 700 career home runs.

In the Classic, Assad held Team USA's potent and hardware-packed lineup to a 1-for-10 showing in Mexico's 11-5 win in pool play. Assad then logged 2 2/3 critical innings for Team Mexico in a 5-4 victory over Puerto Rico in the quarterfinals.

They were the type of performances that had Ross imagining Assad as a bridge arm in the bullpen, if the rotation job were to go to Wesneski or Adrian Sampson.

"What he was doing in the WBC in that environment," Ross said, "coming out of the 'pen, for me, it reminded me a lot of Keegan Thompson and what he did for us last year during the season."

While Assad was away, his teammates back in Cubs camp were paying attention. There were mornings when Chicago players were chatting about the pitcher's outings in the clubhouse. His phone was buzzing with texts after his appearances.

"He was filthy," Stroman said. "He looked really good."

"He was electric, man," Cubs veteran Kyle Hendricks said. "He was so fired up out there, too."

Hendricks said he saw a new side of Assad, who had a few moments in the Classic where he had outburst of celebration after strikeouts.

"It's funny," Hendricks said. "Walking around here, he's the most mild-mannered, calm guy you could ever imagine."

In the coming days, Assad will find out if he pitched his way into the Opening Day plans.

"I'm going to be wherever I'm supposed to be," he said.