A plan to dramatically alter the upper deck in right field at Coors Field is “under serious consideration,” according to a Rockies source.

The team has sketched out potential plans that include a restaurant and even a party deck. The Rockies have taken bids from construction companies, an indication of their desire to move forward with the major project that would alter the appearance of the Lower Downtown stadium, which debuted in 1995.

While basking in major-league attendance records for two years at Mile High Stadium, the decision was made to include the third deck above the bullpens so the park would accommodate 50,000 fans. With total home attendance settling around 2.5 million over the last nine seasons, Coors Field’s size has became excessive.

Seating capacity won’t be reduced dramatically, however, because there would be paid seats in the restaurant, similar to the Press Club added this year where media seating previously existed.

Standing-room-only tickets likely would be available too, leaving a guess of 3,000 fewer seats overall.

Following the lead of other Major League Baseball franchises, the Rockies added the Press Club, which sold out quickly, as a way to create more revenue through premium seating. The transformation of the upper deck in right field could create a “fan experience” — if the Rockies go with live bands before games, for example — that doesn’t exist at the 18-year-old ballpark now.

Roster shuffle removes E.Y. Needing a safety net for the rotation and satisfied with Tyler Colvin’s progress, the Rockies designated popular outfielder Eric Young Jr. for assignment Wednesday to clear a roster spot for long reliever Chris Volstad.

“We needed to protect our pitching,” said assistant general manager Bill Geivett.

“There’s been an attachment to E.Y. since he’s been here. He brought toughness and energy. He’s one of my all-time favorites as a guy.”

The Rockies have 10 days to trade or release Young. The Mets and Astros represent potential fits.

After his release before Wednesday’s game, Young tweeted: “Best wishes to the Rockies organization. Thank you for my time with you. Truly a blessing to be with the city of Denver. Thank you all for the support. Love you all.”

Young provided a spark off the bench a year ago and won a job in spring training, but he failed to gain traction this season.

He struggled to get on base consistently, and his defensive regression became noticeable in recent weeks. Colvin provides more power and versatility.

The Rockies’ pitching staff has become vulnerable after a taxing road trip, minor injuries to Jorge De La Rosa (finger) and Tyler Chatwood (right triceps) and a four-inning outing by Thursday starter Jeff Francis.

Footnotes. Chatwood will return Saturday, leaving Juan Nicasio to pitch against the Phillies in the series opener Friday. … Troy Tulowitzki popped into first-round draft pick Jonathan Gray’s news conference Wednesday to introduce himself, leaving the pitcher a bit awestruck.

Troy E. Renck: 303-954-1294, trenck@denverpost.com or twitter.com/troyrenck