Yes, you can.
Get an early bus to Ortisei and take the 2 stage cable way to Seceda. For an easy hike, walk out on Trails 1 and 6 to Forcella Pana, a 40 minute roundtrip.
Descend to Ortisei and walk through the village and across the highway to the Mont Sëuc lift. From the top you can walk an easy 3.8 miles to Compatsch (Trails 9, 6, 3 and 30 all well marked) in 2 hours. You could have lunch at Mont Sëuc before you set off or at the charming Hotel Icaro along the way.
Once in Compatsch, you can take the big blue gondolas down to Siusi and return to Castelrotto by bus from there, a very short ride.
Editing to clarify Mont Sëuc is on the Seiser Alm, aka Alpe di Siusi.