The Baltimore Orioles open their 1977 baseball season at home today at Memorial Stadium at 2 p.m., with pitcher Jim Palmer matched against Bert Blyleven of the Texas Rangers.

Box and preferred-reserve seats are sold out for the game, but 18,000 general admission and about 3,000 bleacher seats will go on sale at noon today at the stadium. General admissions seats are $2 for adults and $1.25 for senior citizens and children under 12 years; bleacher seats are $1.

In addition, there are some upper-reserved ($3) and lower-reserved ($3.25) seats available. Senior high school and college students with identification may purchase an upper-reserved for $1.50. An Orioles spokesman noted that the entire upper deck of wooden, backless seats have been replaced by aluminum benches with individual backs.

Today's game will be the first time in 21 years that third-baseman Brooks Robinson will not be in the Orioles' starting lineup, having been replaced by Doug DeCinces. Washington-born Elliott (Bump) Wills will be at second base for the Rangers.

The Orioles, who finished second in the American League East last year with a 97-62 record, are missing 14 of the players who were on last year's opening-day roster. The first ball will be thrown from the radio booth by Oriole sportscaster Chuck Thompson and Bill O'Donnell.

Club officials also confirmed yesterday that Palmer had mailed a $500 check to the AL office to pay a fine he incurred last year for hitting the Yankees' Mickey Rivers in the back with a ball after Dock Ellis hit Reggie Jackson. Palmer would have been barred from pitching this season if the fine was not paid.