ST. PETERSBURG — Charlie Morton knows that he is issuing more walks than usual this season, and he’s been around long enough to realize that eventually it will hurt him.They haven’t so far. The Rays right-hander enters his start against the Miami Marlins on Tuesday night with a 3-0 record and 2.64 ERA in eight starts. That’s despite a walk rate of 11.4 percent, which is the highest of his big-league career. Morton owned a walk rate of 9.2 percent last season, and has a career rate of 8.7 percent.In his most-recent start last Wednesday, Morton issued four walks in his five-inning outing against the Diamondbacks. He allowed two runs, and both of those runs reached base off leadoff walks to Arizona centerfielder Jarrod Dyson.The free passes haven’t really hurt Morton for a few reasons. First off, he’s not allowing many hits, just 33 in 44 1/3 innings, and opponents are batting just .207 against him, which would stand as the best of his career. Morton has allowed four or fewer hits in six of his eight starts.And while Morton might be allowing base runners with walks, he’s been successful stranding them. His 81.5 percent left-on-base percentage is eighth-best among qualifying AL starters.He's also been able to offset his walks with a 30.4 percent strikeout rate, which ranks sixth in the AL, but Morton said that won't continue to get away with the high walk totals.“It’s not sustainable,” Morton said Sunday. “So ideally it’s make them hit the ball at least to get on. I think the walks will come down as the season progresses and I get a better feel for my pitches and my delivery. That’s my hope.”That definitely makes sense. While Morton generates a high amount of swinging strikes (12.3 percent, tied for 10th in the AL), when pitches are put in play, they haven’t often been well hit. His 27.2 percent hard-hit rate is the second-best mark among qualifying AL starters.Interestingly enough, Blake Snell ranks third (27.5 percent) and Tyler Glasnow is fifth (28.8).As for Morton, facing a Marlins team that owns the majors’ worst record should be good for him. Miami draws the second-fewest walks in the game — the Marlins’ 7.1-percent walk rate ranks 29th of MLB’s 30 teams — and their .219 team batting average is tied for second-to-last in the majors. Contact Eduardo A. Encina at email@example.com. Follow @EddieInTheYard.