Brian Goodwin (Greg Fiume/Getty Images) Brian Goodwin (Greg Fiume/Getty Images)

Brian Goodwin was named to his second straight Arizona Fall League all-star team roster and will compete in the Rising Stars Game on Saturday, which will be broadcast live at 8 p.m. Eastern on MLB Network. Goodwin, the Nationals’ top hitting and outfield prospect, has been working to improve his hitting since the instructional league and has garnered some early positive reviews.

Goodwin, 23, a first-round pick in the 2011 draft, is hitting .304/.339/.411 with one home run, three doubles and two stolen bases through 13 games for the Mesa Solar Sox as of Friday morning. This year, in only his second full professional season, he hit .252/.355/.407 with 10 home runs, 19 doubles, 11 triples and 19 stolen bases in 30 tries at Class AA Harrisburg. He struck out 121 times while drawing 60 walks.

Before the fall league, the Nationals worked with him in the instructional league to improve his hitting approach and swing. His swing was too choppy and he was double-tapping with his lower half during his stride. So coaches worked with him to limited that so that his swing could be more fluid. “It enables him to see the ball longer and cover the strike zone better,” said Nationals director of player development Doug Harris.

In the fall league, “he has played really good defense out there and ran the bases well,” Harris added. “But it’s really continuing to fine-tune that approach and swing.”

Much is expected from Goodwin and his future, so it’s easy to forget that he hasn’t been in professional baseball that long. He still needs time to develop before he is ready to push for the major leagues and man the outfield alongside Jayson Werth and Bryce Harper. His numbers were better in the 2012 season — when he hit .324/.438/.542 with nine home runs in 58 games with Class A Hagerstown — but then they dipped down once he was promoted to Harrisburg before coming back up in his full season there in 2013.

“He’s a very gifted young man and with that comes certain expectations,” Harris said. “I think he had a tremendous year in ’12 statistically. We challenged him this year. I think he learned a ton. The game is one of adjustments and he was forced to make some adjustments this year. I think he has a better understanding of the details of his game and what he needs to do to be successful. I think it’s a big learning year for him.”

Catcher Adrian Nieto, 23, who hit .285 for Class A Potomac this season, was added late Friday to the all-star roster. He is hitting .286/.382/.393 with five walks in eight games. The areas of most improvement for him are behind the plate.

“He has been much of same that we saw during the regular season,” Harris said. “He does a nice job handling the pitchers. For him, it’s continuing to learn how to manage and call a game. Offensively, he’s performed well.”

Other Nationals prospects had strong cases, too, for all-star bids but the voting was limited. Left-handed starter Matt Purke was recently award league pitcher of the week honors. In three starts last week, he went 2-0, allowing three hits, only one unearned run, three walks while striking out 12 over 12 innings. Purke, who was finally healthy this year after 2012 shoulder surgery and reached Class A Potomac, has overall a 3.00 ERA over 15 innings.

“The biggest thing with Matthew is commanding his fastball,” Harris said. “When he has fastball command, he puts himself in a good position to succeed out there. His velocity is good. He’s been up to 94. Good life on his fastball. We’re very encouraged about what has been coming out of his hand. He is strong physically and we feel really good. He built a good foundation over the course of the summer and built up a body of work that will bode well for 2014.”

Another left-handed starter building up his innings after major surgery, Sammy Solis, who had Tommy John surgery in spring 2012 and is also throwing well in Arizona. Solis, who was at Potomac last season, has a 2.29 ERA over 19 2/3 innings. Solis also missed some time this summer with a shoulder injury so the more he pitches the better position he will be in next season.

Steven Souza Jr. has played well in limited action, going 10 for 29 (.345) in only eight games. Souza will an interesting prospect to watch: he is 6-foot-3, 220 pounds and athletic, he has adjusted to every minor league level he is at, he put up good numbers at Harrisburg this season (.300/.396/.557 with 15 home runs in 77 games) and he is 24 years old. With Dan Haren and Chad Tracy leaving the Nationals via free agency, Souza was added to the 40-man roster on Friday.

Right-handed reliever Robert Benincasa, 23 who is in only his first full professional season and is being tested physically. has a 4.50 ERA over eight innings. Richie Mirowski, 24, also a right-handed reliever, has a 1.29 ERA over seven innings, picking right up where he left off during the regular season. He posted a combined 1.83 ERA, 11.5 strikeout rate and 5.87 K/BB ratio between Potomac and Harrisburg this season.

“He’s learning a little cut fastball out there,” Harris said. “He’s got a good curveball and good split change. Learning a cutter is another weapon for him.”