SEATTLE -- The buzz surrounding Frankie Montas as one of baseball¡¯s most sought-after pitchers ahead of the Aug. 2 Trade Deadline has only heightened with each start. However, an early exit on Sunday now leaves his immediate future in question.

On a cold Seattle afternoon with heavy rainfall in the surrounding area at the first pitch, gloom came over T-Mobile Park¡¯s visiting dugout as the A¡¯s saw their ace depart Sunday¡¯s 2-1 loss against the Mariners after just one inning with tightness in the back of his right shoulder.?

There was an immediate cause for concern with how Montas¡¯ stuff looked in the first. Surrendering a leadoff homer to Julio Rodr¨ªguez as part of a 13-pitch frame, Montas maxed out at just 94.5 mph with his fastball, a pitch that had reached as high as 99.1 mph over his previous two outings. Overall, Montas¡¯ velocity on his four-seamer was 2.4 mph slower than his season average, while the velocity on his sinker was 2.7 mph lower.

After an evaluation of Montas¡¯ shoulder by team doctors revealed some inflammation, he is expected to undergo an MRI when the A¡¯s return to Oakland on Monday to determine the severity of the issue.

¡°Frankie went out in that first inning and we noticed that the velo was down,¡± said manager Mark Kotsay. ¡°We checked in with him after he came in and he had some tightness and just didn¡¯t feel like he could get fully extended. In that situation, we¡¯re gonna err on the side of caution.¡±

Montas noted that an inability to recover the way he normally does after a start following his outing at Yankee Stadium earlier in the week may have been a contributing factor to Sunday¡¯s alarming situation. While the soreness felt no different to what he¡¯s experienced throughout the year, seeing his velocity readings on the stadium radar gun was an uneasy feeling for both Montas and the A¡¯s training staff, leading to a joint decision to end his outing.

¡°I¡¯m always sore,¡± Montas said. ¡°Usually I¡¯ll go out there and pitch and it gets better. But my velo has never been down. I felt like the best thing was to come out of this game and take a better look at [the shoulder].¡±

Emerging as a workhorse for the A¡¯s who has ranked among the AL's leaders in innings pitched over the past two years, Montas has managed to avoid a stint on the injured list as a Major Leaguer for the entirety of his seven big league seasons. Initial strength tests revealed no sign of a major injury. While Monday¡¯s MRI will provide a better idea of how much time, if any, he might have to miss, Montas remained positive about his outlook postgame.

¡°I¡¯m going to get the MRI when we get back home and we¡¯ll just go from there,¡± Montas said. ¡°I don¡¯t think it¡¯s anything bad, just soreness and maybe some inflammation. Nothing that I¡¯m worried about.¡±

Though the A¡¯s entered a rebuild this spring by trading away several stars, they held off on dealing away Montas in hopes of receiving a better offer during the season. Based on the right-hander¡¯s numbers, that move appeared to be the right one. Entering Sunday, Montas held a 3.20 ERA over 16 starts. Among American League starters, Montas had ranked fifth in innings pitched (95 2/3), seventh in strikeouts (99), eighth in WHIP (1.09) and 12th in opponents¡¯ batting average (.226).

For a scuffling last-place A¡¯s club that entered the day off to its second-worst 80-game start to a season (26-54) since moving to California in 1968 and on pace to lose an Oakland record 110 games, Montas has been one of the few bright spots as a potential All-Star candidate. For a young A¡¯s clubhouse that often looks to Montas for leadership, losing him for any amount of time would certainly be a blow.

¡°He and Paul [Blackburn] have been our aces this year,¡± said A¡¯s shortstop Elvis Andrus, who homered on Sunday. ¡°Hopefully, it¡¯s nothing serious. Maybe just a little bit of swelling and he¡¯ll be back on the mound, because we want him. Every time he or Pauly is pitching, we know we have a high probability of winning that day. I want all my teammates to be healthy. I hope it¡¯s nothing crazy and he can be back pretty soon.¡±