BOSTON — Matt Barnes is a difficult pitching prospect to read nowadays.

While there’s an understanding that Eduardo Rodriguez, Henry Owens and Brian Johnson — three other Red Sox pitching prospects who’ve worked at both Triple-A and the major league level this season — all have futures in the starting rotation, whether in Boston or elsewhere, Barnes is a rather mysterious breed. Each time he takes the mound, the big question looms: Where exactly does he fit for 2016?

Barnes made his second big league start Saturday in the Red Sox’s 6-3 loss to the Kansas City Royals at Fenway Park. It did little to answer the prevailing question, other than to suggest that he probably needs more seasoning in the minors before excelling in the majors in either capacity (starter or reliever).

This isn’t to say Barnes’ start was a total disaster. The right-hander can learn from and build on each time he toes a major league rubber. But surrendering five runs on eight hits, including a home run, over 5 1/3 innings hardly represents a notable step forward from the six-run, six-hit, five-inning effort he provided in his first start Monday against the Cleveland Indians.

In Barnes’ defense, he was one pitch away from posting a far better stat line against Kansas City. He left a 1-1 fastball out over the plate to Salvador Perez in the sixth inning, and the All-Star catcher smoked it into the Red Sox’s bullpen for a three-run homer that put the Royals in front 5-0.

“You’re not going to succeed without some struggle first,” Barnes said after the game. “Those are situations you learn from. Even if the result isn’t what you want, I think you almost learn more from that than if you execute every single time.”

The problem isn’t with Barnes struggling from time to time, though. That’s part of being a young player. Heck, that’s part of life.

The problem is that Barnes has yet to gravitate toward either role (starter or reliever). He’s left much to be desired while pitching in either capacity — something that isn’t entirely his fault — and the Red Sox, as a result, can’t really make any definitive determinations on his long-term future.

The club’s hope, presumably, was that Barnes would seize his opportunity as a reliever earlier this season and give the Red Sox a much-needed power arm at the back end of the bullpen. They then could determine in time whether to transition Barnes back into a starting role, though the ghost of Daniel Bard always lurks when one begins to discuss such flip-flopping. It never panned out, of course, as Barnes posted a 5.64 ERA and a 1.88 WHIP in 21 relief appearances spanning 22 1/3 innings. He looked uncomfortable, almost as if he had been thrown into a situation for which he was unprepared.

Now, Barnes is back starting baseball games, mostly because injuries to Johnson, Rick Porcello, Clay Buchholz and Steven Wright have backed the Red Sox into a corner. And unfortunately for Boston, the 25-year-old hasn’t done much in two major league starts to prove that starting should be his go-to gig.

It’s a tricky situation, obviously. The Red Sox need to balance team needs with the needs of the player as far as development goes. Boston faced a similar starter-reliever conundrum with Brandon Workman in 2013 and 2014 before he eventually underwent Tommy John surgery.

The Red Sox can take solace in the fact that Barnes is healthy and willing to roll with what has seemed like a trial-and-error approach to this point. But compounding errors can prove problematic. And right now, Barnes, a former first-round pick, is without a clear path. He’s essentially stuck in the middle.

That’s a tough place to be with evaluations for 2016 well underway.

Thumbnail photo via Mark L. Baer/USA TODAY Sports Images