Besides appearing as the center fielder on the Topps All-Rookie team, this is Del Unser's rookie card. Among its other shortcomings, the 1968 Topps set was missing some key 1968 rookies: Reggie Jackson, Bobby Bonds, Sparky Lyle, Andy Messersmith, Joe Rudi, and Del Unser all played significant roles for their teams that season. (Jackson and Lyle had actually played quite a bit in 1967 as well.)
Unser made his major-league debut on opening day 1968, and started 154 of the Senators' 161 games in center field that season. Del was the team's leadoff batter for 148 of those starts. His first day off did not occur until May 25th.
Despite only batting .230 and hitting just 1 home run, Unser finished 2nd in the AL Rookie of the Year voting.
For more on Del Unser's career, check out this post on my 1970 Topps blog.