Doubt is a funny thing.

On the one hand, it makes us stop and think before acting too hastily and rushing into something. On the other hand, doubt also can prevent you from achieving goals or question your own self worth.

Doubt is constant in fantasy baseball. Did you give up on that underachieving pitcher too early? In your head you start to say, “The expected stats say he’s going to turn it around, but should I wait? There have been no fewer than 20 players I could’ve picked up to help me close that six-game gap between me and the first-place team. Maybe I should drop him. But, what if he turns it on? Wait … did I leave the iron on?”

Roto Rage’s advice: Trust your gut. Not all your moves will work out, but at least you had the guts to swing for the fences.

Year after year, Jon Gray was one of those pitchers who would be listed among the potential breakout candidates. Year after year, Gray would show flashes. Year after year, Gray would ultimately never fully live up to the hype.

Then, the right-hander left Colorado …

After a rough April and May (1-2, 5.56 ERA, .248 opponents average), the 30-year-old Ranger has turned things around in a pretty big way.

Over his past 10 starts (since June 1), Gray has allowed more than three earned runs just twice while going 6-2 with a 2.34 ERA and .204 opponents’ average. He has won six of his past seven starts while maintaining a 1.85 ERA with a 48-7 strikeout-walk rate, .209 opponents average and .579 OPS.

During that 10-game stretch, he had the second most wins (six) in the majors, the 13th-best strikeouts per nine (10.65), the 11th-best ERA (2.34) and the 19th-best swinging strike rate (12.6 percent). He had a 2.88 FIP and 2.90 xFIP in that span.

Gray entered the weekend with the ninth-best strikeout rate (27 percent), 22nd-best opponents average (.218) and ranked 17th in swinging strike rate (12.2 percent). He also ranked 33rd in ERA (3.42) and 27th in WHIP (1.12, a career-best mark). Over seven seasons with the Rockies, Gray’s ERA finished under 4.00 just twice and never finished under 3.50.

Though Gray’s fastball can hit 98 mph, opposing hitters are hitting .279 against it. He does his damage with his slider — a pitch he is using 36.3 percent of the time. Opponents are hitting .159 against it with a 40.3 percent whiff rate and 21.5 percent swinging-strike rate. His expected stats also support the success of his slider.

Gray’s xERA (3.54) is ever-so-slightly above his ERA, his FIP (3.28) and xFIP (3.27) show his performance is legit — and could potentially improve in the second half, even with a challenging schedule.

After pitching six scoreless innings against Miami on Thursday, Gray’s potential schedule may not look like it would work in his favor. Barring injuries or unexpected interruptions to the schedule, he is scheduled to pitch seven of his next 11 starts on the road, where he is 3-4 with a 3.74 ERA, 1.18 WHIP and .224 opponents average in 12 road starts. His opponents could include the Mariners, Angels, Astros (twice), Twins, Red Sox and Marlins.

Roto Rage says don’t let doubt creep into your head and wait until he is home, where he has had far more success (4-0, 2.93 ERA, 0.98 WHIP, 12.3 K/9 in five starts), to put him in your rotation. He isn’t in Colorado any more.

If you need dependable pitchers in your lineup, Gray is proving he can and will be just that (even with an occasional dud). Don’t doubt it.

Matt Carpenter 2B/DH, Yankees

Before going 0-for-7 in Thursday’s twin bill, he hit .442 with seven homers, 21 RBIs, 12 runs and 1.023 OPS in his first 13 games this month.

Paul Sewald RP, Mariners

Allowed two earned runs over his past 14 appearances, going 8-for-8 in save chances while striking out 20, walking one and limiting opponents to a .130 average. Owned in less than 40 percent of ESPN leagues.

Leody Taveras OF, Rangers

Entered Friday on a nine-game hit streak, going 16-for-35 (.457) with a homer, 11 RBIs, nine runs, four stolen bases and 1.258 OPS in that span.

Harold Ramirez 1B/OF, Rays

In 39 games since June 1, he hit .384 with 22 RBIs, 17 runs, two stolen bases and .956 OPS. He had at least one hit in 31 of those games.

Isaac Paredes 2B/3B, Rays

Had no homers since hitting two on July 2, going 7-for-42 (.167) with one RBI, nine strikeouts and .476 OPS in 11 games since.

MacKenzie Gore SP, Padres

Went 4-1 with a 1.50 ERA in his first nine appearances, but was 0-3 with a 10.89 ERA, 14-18 strikeout-walk rate and .341 opponents average in his past six.

Eddie Rosario OF, Braves

In his first 12 games since returning from the IL, he was hitting .195 with 11 strikeouts, no walks, a .186 on-base percentage and .552 OPS.

Nick Pivetta SP, Red Sox

No wins since June 24, going 0-2 with a 10.24 ERA, 10 walks and .342 opponents average in his past four starts. Allowed four homers and 20 earned runs over his past 13 ¹/₃ innings (13.50 ERA).

No Diggity, No Trout