SAN FRANCISCO -- With a postseason spot long gone, the Giants hoped to take a look at some of their top prospects in September. Another injury will likely keep that from being a reality for the organization's top minor league pitcher.

Right-hander Tyler Beede is expected to miss the rest of the season after suffering a groin strain while warming up for his last start, NBC Sports Bay Area has learned. Beede, a first-round pick in 2014, will be sidelined at least four weeks, but he is headed to the club's facility in Scottsdale to rehab and keep open the possibility of being ready at some point in September.

The more likely scenario is that Beede pitches in the Arizona Fall League after the season in order to get more innings under his belt. After throwing 147 1/3 innings in Double-A last year, he was at 109 innings in Triple-A at the time of his injury. Beede is viewed as a 2018 rotation option, so the Giants will need him to get more work in before this year is over.

The timing is brutal, and not just because Beede was potentially a month away from a September call-up. When he got hurt, Beede was coming off one of his best starts of his season with the River Cats. He allowed just one unearned run in seven innings on July 19, striking out five and walking one. Teammates raved about the stuff Beede showed that day, but he wasn't able to build off the start. He got hurt while warming up in the bullpen for his following start.

The 24-year-old battled inconsistency at times in Sacramento, but of his final five starts with the River Cats, three were of at least seven innings with two-or-fewer earned runs. He certainly looked headed for a September call, and at times this year, he has been mentioned by team officials as a potential starter down the stretch. Overall, Beede had a 4.79 ERA in 19 starts. His final month was his best; he posted a 3.57 ERA in July.

It's been an odd season for the Giants in terms of developing prospects. Christian Arroyo likely would have been called up after the Eduardo Nuñez trade, but he is also in Arizona, rehabbing after hand surgery. Austin Slater seemed to win the left field job, but a groin injury has him out for a couple of months and the Giants now want him to play winter ball to get extra at-bats. Arroyo and Slater have not officially been ruled out for the rest of the season, but it'll be hard for the Giants to get either player ready by the end of September.