Last winter, the Mets brought Collin Cowgill as a potential platoon piece in the outfield, who could play center field. He did show a platoon split - hitting lefties better than righties, but did not hit anyone well enough to keep his place on the Mets' forty-man roster. Marte, by the way, has hit .254/.368/.337 with 14 walks, 25 strikeouts and no homeruns in 25 games for the for the A's AA Midland team. However, the 22-year-old has been hobbled since May 3 by a strained calf that has limited to just an inning an a half in the last two months.
Johnson, a right-handed hitting outfielder was hitting .308/.416/.421 in 68 games for the Burlington Bees in the Midwest League (the same level as Savannah). He had 16 doubles, 39 walks and was 30-for-35 stealing bases. The 23-year-old was 8th in the MWL in batting average, and fourth in on-base percentage and stolen bases. He can certainly help the Savannah Sand Gnats, who are dead least in the SAL in stolen bases specifically and who could use the offensive help more generally following the promotion of Jayce Boyd and Kevin Plawecki to advanced-A St. Lucie. Johnson has mostly played right field, but has manned centerfield eight times.
The Angels originally drafted Johnson in the 23rd round of the 2012 draft from Washington State.
I suspect that adding him to the Gnats' roster gives the Mets some insurance if they decide to promote Brandon Nimmo at some point in the second half. Just to be clear, I do not think that move is imminent, as Nimmo has not been hitting well enough recently (.250/.356/.368 in 20 games in June) to suggest that he deserves a move or that it would be productive developmentally.
On age alone, Johnson is very unlikely to crack my Mets Top 41 prospects next year. On merit this year, Cowgill could not hold onto a Mets' 40-man roster spot. That all seems to make sense. At least the Mets are getting a guy who can help an affiliate in the next few years through his patience and speed.