The 28-year-old arrived at the Camp Nou in 2011, but injuries have limited him to just 35 appearances for the Spanish club in all competitions.
He has now linked up with Olympiacos, who have the option to extend the Dutchman's stay with them by a further two years.
It is Afellay's second loan stint since he joined Barca, having spent the 2012-13 campaign with Schalke 04 in the Bundesliga.
Restore Data
| Team | P | W | D | L | F | A | GD | PTS | |
| 1 | Real Madrid | 31 | 24 | 6 | 1 | 67 | 20 | 47 | 78 |
| 2 | Barcelona | 31 | 21 | 7 | 3 | 62 | 34 | 28 | 70 |
| 3 | GironaGirona | 31 | 20 | 5 | 6 | 63 | 39 | 24 | 65 |
| 4 | Atletico MadridAtletico | 31 | 19 | 4 | 8 | 59 | 36 | 23 | 61 |
| 5 | Athletic Bilbao | 31 | 16 | 9 | 6 | 51 | 29 | 22 | 57 |
| 6 | Real Sociedad | 31 | 13 | 11 | 7 | 45 | 33 | 12 | 50 |
| 7 | Valencia | 31 | 13 | 8 | 10 | 34 | 32 | 2 | 47 |
| 8 | Real BetisBetis | 31 | 11 | 12 | 8 | 38 | 37 | 1 | 45 |
| 9 | Villarreal | 31 | 10 | 9 | 12 | 49 | 54 | -5 | 39 |
| 10 | Getafe | 31 | 9 | 12 | 10 | 37 | 43 | -6 | 39 |
| 11 | Osasuna | 31 | 11 | 6 | 14 | 36 | 44 | -8 | 39 |
| 12 | Las PalmasLas Palmas | 31 | 10 | 7 | 14 | 29 | 35 | -6 | 37 |
| 13 | Sevilla | 31 | 8 | 10 | 13 | 39 | 44 | -5 | 34 |
| 14 | AlavesAlaves | 31 | 8 | 8 | 15 | 26 | 38 | -12 | 32 |
| 15 | Mallorca | 31 | 6 | 13 | 12 | 25 | 36 | -11 | 31 |
| 16 | Rayo Vallecano | 31 | 6 | 13 | 12 | 25 | 38 | -13 | 31 |
| 17 | Celta Vigo | 31 | 6 | 10 | 15 | 33 | 46 | -13 | 28 |
| 18 | CadizCadiz | 31 | 4 | 13 | 14 | 21 | 41 | -20 | 25 |
| 19 | Granada | 31 | 3 | 8 | 20 | 32 | 60 | -28 | 17 |
| 20 | Almeria | 31 | 1 | 11 | 19 | 30 | 62 | -32 | 14 |
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